Glossary
Numbers and Symbols
* (star) Integrity Axiom (* Axiom)
An axiom of the Biba model that states that a subject at a specific classification level cannot write data to a higher classification level. This is often shortened to “no write up.”
* (star) Security Property (* Property)
A property of the Bell-LaPadula model that states that a subject at a specific classification level cannot write data to a lower classification level. This is often shortened to “no write down.”
802.11i (WPA-2)
An amendment to the 802.11 standard that defines a new authentication and encryption technique that is similar to IPSec. To date, no real-world attack has compromised a properly configured WPA-2 wireless network.
802.1x
A form of wireless authentication protection that requires all wireless clients to pass a gauntlet of RADIUS or TACACS services before network access is granted.
1000Base-T
A form of twisted-pair cable that supports 1000Mbps or 1Gbs throughput at 100 meter distances. Often called Gigabit Ethernet.
100Base-TX
Another form of twisted-pair cable similar to 100Base-T.
10Base2
A type of coaxial cable. Often used to connect systems to backbone trunks. 10Base2 has a maximum span of 185 meters with maximum throughput of 10Mpbs. Also called thinnet.
10Base5
A type of coaxial cable. Often used as a network’s backbone. 10Base5 has a maximum span of 500 meters with maximum throughput of 10Mpbs. Also called thicknet.
10Base-T
A type of network cable that consists of four pairs of wires that are twisted around each other and then sheathed in a PVC insulator. Also called twisted-pair.
A
abnormal activity
Any system activity that does not normally occur on your system. Also referred to as suspicious activity.
abstraction
The collection of similar elements into groups, classes, or roles for the assignment of security controls, restrictions, or permissions as a collective.
acceptance testing
A form of testing that attempts to verify that a system satisfies the stated criteria for functionality and possibly also for security capabilities of a product. It is used to determine whether end users or customers will accept the completed product.
accepting risk
The valuation by management of the cost/benefit analysis of possible safeguards and the determination that the cost of the countermeasure greatly outweighs the possible cost of loss because of a risk.
access
The transfer of information from an object to a subject.
access control
The mechanism by which subjects are granted or restricted access to objects.
access control list (ACL)
The column of an access control matrix that specifies what level of access each subject has over an object.
access control matrix
A table of subjects and objects that indicates the actions or functions that each subject can perform on each object. Each column of the matrix is an ACL. Each row of the matrix is a capability list.
access tracking
Auditing, logging, and monitoring the attempted access or activities of a subject. Also referred to as activity tracking.
account lockout
An element of the password policy’s programmatic controls that disables a user account after a specified number of failed logon attempts. Account lockout is an effective countermeasure to brute-force and dictionary attacks against a system’s logon prompt.
accountability
The process of holding someone responsible (accountable) for something. In this context, accountability is possible if a subject’s identity and actions can be tracked and verified.
accreditation
The formal declaration by the Designated Approving Authority (DAA) that an IT system is approved to operate in a particular security mode using a prescribed set of safeguards at an acceptable level of risk.
ACID model
The letters in ACID represent the four required characteristics of database transactions: atomicity, consistency, isolation, and durability.
active content
Web programs that users download to their own computer for execution rather than consuming server-side resources.
ActiveX
Microsoft’s component object model (COM) technology used in web applications. ActiveX is implemented using any one of a variety of languages, including Visual Basic, C, C++, and Java.
Address Resolution Protocol (ARP)
A subprotocol of the TCP/IP protocol suite that operates at the Data Link layer (layer 2). ARP is used to discover the MAC address of a system by polling using its IP address.
addressing
The means by which a processor refers to various locations in memory.
administrative access controls
The policies and procedures defined by an organization’s security policy to implement and enforce overall access control. Examples of administrative access controls include hiring practices, background checks, data classification, security training, vacation history reviews, work supervision, personnel controls, and testing.
administrative law
Regulations that cover a range of topics from procedures to be used within a federal agency to immigration policies that will be used to enforce the laws passed by Congress. Administrative law is published in the Code of Federal Regulations (CFR).
administrative physical security controls
Security controls that include facility construction and selection, site management, personnel controls, awareness training, and emergency response and procedures.
admissible evidence
Evidence that is relevant to determining a fact. The fact that the evidence seeks to determine must be material (in other words, related) to the case. In addition, the evidence must be competent, meaning that it must have been obtained legally. Evidence that results from an illegal search would be inadmissible because it is not competent.
Advanced Encryption Standard (AES)
The encryption standard selected in October 2000 by the National Institute for Standards and Technology (NIST) that is based on the Rijndael cipher.
advisory policy
A policy that discusses behaviors and activities that are acceptable and defines consequences of violations. An advisory policy discusses the senior management’s desires for security and compliance within an organization. Most policies are advisory.
agent
Intelligent code objects that perform actions on behalf of a user. They typically take initial instructions from the user and then carry on their activity in an unattended manner for a predetermined period of time, until certain conditions are met, or for an indefinite period.
aggregate functions
SQL functions, such as COUNT(), MIN(), MAX(), SUM(), and AVG(), that can be run against a database to produce an information set.
aggregation
A number of functions that combine records from one or more tables to produce potentially useful information.
Agile Software Development
A set of software development approaches that eschew the rigid models of the past in favor of approaches that place an emphasis on the needs of the customer, and on quickly developing new functionality that meets those needs in an iterative fashion.
alarm
A mechanism that is separate from a motion detector and triggers a deterrent, triggers a repellant, and/or triggers a notification. Whenever a motion detector registers a significant or meaningful change in the environment, it triggers an alarm.
alarm triggers
Notifications sent to administrators when a specific event occurs.
amplifier
See repeater.
AND
The operation (represented by the ∧ symbol) that checks to see whether two values are both true.
analytic attack
An algebraic manipulation that attempts to reduce the complexity of a cryptographic algorithm. This attack focuses on the logic of the algorithm itself.
annualized loss expectancy (ALE)
The possible yearly cost of all instances of a specific realized threat against a specific asset. The ALE is calculated using the formula ALE = single loss expectancy (SLE) * annualized rate of occurrence (ARO).
annualized rate of occurrence (ARO)
The expected frequency that a specific threat or risk will occur (in other words, become realized) within a single year.
anomaly detection
See behavior-based detection.
APIPA
See automatic private IP addressing (APIPA).
applet
Code objects sent from a server to a client to perform some action. Applets are self-contained miniature programs that execute independently of the server that sent them.
Application layer
Layer 7 of the Open Systems Interconnection (OSI) model.
application-level gateway firewall
A firewall that filters traffic based on the Internet service (in other words, application) used to transmit or receive the data. Application-level gateways are known as second-generation firewalls.
assembly language
A higher-level alternative to machine language code. Assembly languages use mnemonics to represent the basic instruction set of a CPU but still require hardware-specific knowledge.
asset
Anything within an environment that should be protected. The loss or disclosure of an asset could result in an overall security compromise, loss of productivity, reduction in profits, additional expenditures, discontinuation of the organization, and numerous intangible consequences.
asset valuation
A dollar value assigned to an asset based on actual cost and nonmonetary expenses, such as costs to develop, maintain, administer, advertise, support, repair, and replace; as well as other values, such as public confidence, industry support, productivity enhancement, knowledge equity, and ownership benefits.
asset value (AV)
A dollar value assigned to an asset based on actual cost and nonmonetary expenses.
assigning risk
See transferring risk.
assurance
The degree of confidence that security needs are satisfied. Assurance must be continually maintained, updated, and reverified.
asymmetric key
Public key cryptosystems that use a pair of keys (public and private) for each participant. Messages encrypted with one key from the pair can only be decrypted with the other key from the same pair.
asynchronous transfer mode (ATM)
A cell-switching technology rather than a packet-switching technology like Frame Relay. ATM uses virtual circuits much like Frame Relay, but because it uses fixed-size frames or cells, it can guarantee throughput. This makes ATM an excellent WAN technology for voice and video conferencing.
atomicity
One of the four required characteristics of all database transactions. A database transaction must be an “all-or-nothing” affair. If any part of the transaction fails, the entire transaction must be rolled back as if it never occurred.
attack
The exploitation of a vulnerability by a threat agent.
attacker
Any person who attempts to perform a malicious action against a system.
attenuation
The loss of signal strength and integrity on a cable because of the length of the cable.
attribute
A column within a table of a relational database.
audit trails
The records created by recording information about events and occurrences into a database or log file. Audit trails are used to reconstruct an event, to extract information about an incident, to prove or disprove culpability, and much more.
auditing
A methodical examination or review of an environment to ensure compliance with regulations and to detect abnormalities, unauthorized occurrences, or outright crimes.
auditor
The person or group responsible for testing and verifying that the security policy is properly implemented and the derived security solutions are adequate.
authentication
The process of verifying or testing that the identity claimed by a subject is valid.
Authentication Header (AH)
An IPSec protocol that provides authentication, integrity, and nonrepudiation.
authentication protocols
Protocol used to provide the transport mechanism for logon credentials.
Authentication Service (AS)
An element of the Kerberos Key Distribution Center (KDC). The AS verifies or rejects the authenticity and timeliness of tickets.
authorization
A process that ensures that the requested activity or object access is possible given the rights and privileges assigned to the authenticated identity (in other words, subject).
automatic private IP addressing (APIPA)
A feature of Windows that assigns an IP address to a system should DHCP address assignment fail. The IP address range used by APIPA is 169.254.0.0 - 169.254.255.255.
auxiliary alarm system
An additional function that can be added to either local or centralized alarm systems. The purpose of an auxiliary alarm system is to notify local police or fire services when an alarm is triggered.
availability
The assurance that authorized subjects are granted timely and uninterrupted access to objects.
awareness
A form of security teaching that is a prerequisite to training. The goal of awareness is to bring security into the forefront and make it a recognized entity for students/users.
B
badges
Forms of physical identification and/or of electronic access control devices.
Base+Offset addressing
An addressing scheme that uses a value stored in one of the CPU’s registers as the base location from which to begin counting. The CPU then adds the offset supplied with the instruction to that base address and retrieves the operand from the computed memory location.
baseband
A communication medium that supports only a single communication signal at a time.
baseline
The minimum level of security that every system throughout the organization must meet. A baseline can be more than a security baseline. It can also be a performance baseline (used by behavior-based IDSs), or a configuration baseline (used for configuration management).
Basic Input/Output System (BIOS)
The operating system–independent primitive instructions that a computer needs to start up and load the operating system from disk.
Basic Rate Interface (BRI)
An ISDN service type that provides two B, or data, channels and one D, or management, channel. Each B channel offers 64Kbps, and the D channel offers 16Kbps.
behavior
In the context of object-oriented programming terminology and techniques, the results or output from an object after processing a message using a method.
behavior-based detection
An intrusion discovery mechanism used by IDS. Behavior-based detection finds out about the normal activities and events on your system through watching and learning. Once it has accumulated enough data about normal activity, it can detect abnormal and possible malicious activities and events. Also known as statistical intrusion detection, anomaly detection, and heuristics-based detection.
Bell-LaPadula model
A confidentiality-focused security model based on the state machine model and employing mandatory access controls and the lattice model.
best evidence rule
A rule that states that when a document is used as evidence in a court proceeding, the original document must be introduced. Copies will not be accepted as evidence unless certain exceptions to the rule apply.
Biba model
An integrity-focused security model based on the state machine model and employing mandatory access controls and the lattice model.
bind variable
A placeholder for SQL literal values, such as numbers or character strings.
biometrics
The use of human physiological or behavioral characteristics as authentication factors for logical access and identification for physical access.
birthday attack
An attack in which the malicious individual seeks to substitute in a digitally signed communication with a different message that produces the same message digest, thereby maintaining the validity of the original digital signature. This is based on the statistical anomaly that in a room with 23 people, the probability of two of more people having the same birthday is greater than 50 percent.
black-box testing
A form of program testing that examines the input and output of a program without focusing on its internal logical structures.
blackout
A complete loss of power.
block cipher
A cipher that applies the encryption algorithm to an entire message block at the same time. Transposition ciphers are examples of block ciphers.
Blowfish
A block cipher that operates on 64-bit blocks of text and uses variable-length keys ranging from a relatively insecure 32 bits to an extremely strong 448 bits.
bluejacking
Hijacking a Bluetooth connection to eavesdrop or extract information from devices.
Bluetooth (802.15)
A wireless standard commonly used to pair accessories to cell phones or computers.
boot sector
The portion of a storage device used to load the operating system and the types of viruses that attack that process.
bot
An intelligent agent that continuously crawls a variety of websites retrieving and processing data on behalf of the user.
bounds
The limits to the memory and resources a process can access.
breach
The occurrence of a security mechanism being bypassed or thwarted by a threat agent.
bridge
A network device used to connect networks with different speeds, cable types, or topologies that still use the same protocol. A bridge is a layer 2 device.
broadband
A communication medium that supports multiple communication signals simultaneously.
broadcast
A communications transmission to multiple but unidentified recipients.
broadcast address
A broadcast network address that is used during a smurf attack.
brouter
A network device that first attempts to route and then defaults to bridging if routing fails.
brownout
A period of prolonged low voltage.
brute force
An attack pattern characterized by a mechanical series of sequential or combinatorial inputs utilized in an automated attempt to identify security properties (usually passwords) in a given system (see brute-force attack).
brute-force attack
An attack made against a system to discover the password to a known identity (in other words, username). A brute-force attack uses a systematic trial of all possible character combinations to discover an account’s password.
buffer overflow
A vulnerability that can cause a system to crash or allow the user to execute shell commands and gain access to the system. Buffer overflow vulnerabilities are especially prevalent in code developed rapidly for the Web using CGI or other languages that allow unskilled programmers to quickly create interactive web pages.
business attack
An attack that focuses on illegally obtaining an organization’s confidential information.
Business Continuity Planning (BCP)
The assessment of a variety of risks to organizational processes and the creation of policies, plans, and procedures to minimize the impact those risks might have on the organization if they were to occur.
Business Impact Analysis (BIA)
See Business Impact Assessment (BIA).
Business Impact Assessment (BIA)
An analysis that identifies the resources that are critical to an organization’s ongoing viability and the threats posed to those resources. It also assesses the likelihood that each threat will actually occur and the impact those occurrences will have on the business. a.k.a. Business Impact Analysis (BIA)
C
cache RAM
A process by that takes data from slower devices and temporarily stores it in higher-performance devices when its repeated use is expected.
campus area network (CAN)
A network that spans a college, university, or a multibuilding office complex.
capability list
Each row of an access control matrix is a capability list. A capability list is tied to the subject; it lists valid actions that can be taken on each object.
cardinality
The number of rows in a relational database.
cell suppression
The act of suppressing (or hiding) individual data items inside a database to prevent aggregation or inference attacks.
centralized access control
Method of control in which all authorization verification is performed by a single entity within a system.
centralized alarm system
An alarm system that signals a remote or centralized monitoring station when the alarm is triggered.
certificate authority
An agency that authenticates and distributes digital certificates.
certificate revocation list (CRL)
The list of certificates that have been revoked by a certificate authority before the lifetimes of the certificates have expired.
certificates
Endorsed copies of an individual’s public key that verifies their identity.
certification
The comprehensive evaluation, made in support of the accreditation process, of the technical and nontechnical security features of an IT system and other safeguards to establish the extent to which a particular design and implementation meets a set of specified security requirements.
chain of evidence
The process by which an object is uniquely identified in a court of law.
Challenge Handshake Authentication Protocol (CHAP)
One of the authentication protocols used over PPP links. CHAP encrypts usernames and passwords.
change management
The means by which changes to an environment are logged and monitored in order to ensure that any change does not lead to reduced or compromised security.
checklist test
A process in which copies of the disaster recovery checklists are distributed to the members of the disaster recovery team for their review.
Children’s Online Privacy Protection Act (COPPA)
A law in the United States that places specific demands upon websites that cater to children or knowingly collect information from children.
chosen cipher-text attack
An attack in which the attacker has the ability to decrypt chosen portions of the cipher-text message.
chosen plain-text attack
An attack in which the attacker has the ability to encrypt plaintext messages of their choosing and then analyze the cipher-text output of the encryption algorithm.
CIA Triad
The three essential security principles of confidentiality, integrity, and availability.
cipher
A system that hides the true meaning of a message. Ciphers use a variety of techniques to alter and/or rearrange the characters or words of a message to achieve confidentiality.
Cipher Block Chaining (CBC)
A process in which each block of unencrypted text is XORed with the block of cipher text immediately preceding it before it is encrypted using the DES algorithm.
Cipher Feedback (CFB)
A mode in which the DES algorithm is used to encrypt the preceding block of cipher text. This block is then XORed with the next block of plain text to produce the next block of cipher text.
cipher text
A message that has been encrypted for transmission.
civil laws
Laws that form the bulk of the body of laws in the United States. They are designed to provide for an orderly society and govern matters that are not crimes but require an impartial arbiter to settle disputes between individuals and organizations.
Clark-Wilson model
A model that employs limited interfaces or programs to control and maintain object integrity.
class
In the context of object-oriented programming terminology and techniques, a collection of common methods from a set of objects that defines the behavior of those objects.
classification
A label that is applied to a resource to indicate its sensitivity or value to an organization and therefore designate the level of security necessary to protect that resource.
classification level
Another term for a security label. An assigned importance or value placed on objects and subjects.
clean power
Nonfluctuating pure power.
clearing
A method of sufficiently deleting media that will be reused in the same secured environment. Also known as overwriting.
click-wrap license agreement
A software agreement in which the contract terms are either written on the software box or included in the software documentation. During the installation process, you are required to click a button indicating that you have read the terms of the agreement and agree to abide by them.
clipping level
A threshold value used in violation analysis auditing. Crossing the clipping level triggers the recording of relevant event data to an audit log.
closed-circuit television (CCTV)
A security system using video cameras and video recording devices.
closed head system
See wet pipe system.
clustering (or key clustering)
A weakness in cryptography where a plain-text message generates identical cipher-text messages using the same algorithm but using different keys.
coaxial cable
A cable with a center core of copper wire surrounded by a layer of insulation and then by a conductive braided shielding and finally encased in an insulation sheath. Coaxial cable is fairly resistant to EMI, has a low cost, and is easy to install.
Control Objectives for Information and related Technology (CobiT)
A security concept infrastructure used to organize the complex security solution of companies.
code
See cipher.
cohesive (or cohesiveness)
An object is highly cohesive if it can perform a task with little or no help from other objects. Highly cohesive objects are not as dependent upon other objects as objects with lower cohesion. Objects with higher cohesion are often better. Highly cohesive objects perform tasks alone and have low coupling.
cognitive password
A variant of the password authentication factor that asks a series of questions about facts or predefined responses that only the subject should know.
cold sites
Standby facilities large enough to handle the processing load of an organization and with appropriate electrical and environmental support systems.
collision attack
See birthday attack.
collusion
An agreement between multiple people to perform an unauthorized or illegal action.
commercial business/private sector classification
The security labels commonly employed on secure systems used by corporations. Common corporate or commercial security labels are confidential, proprietary, private, sensitive, and public.
Committed Information Rate (CIR)
A contracted minimum guaranteed bandwidth allocation for a virtual circuit.
Common Body of Knowledge (CBK)
The areas of information prescribed by (ISC)2 as the source of knowledge for the CISSP exam.
common mode noise
Electromagnetic interference (EMI) noise generated by the difference in power between the hot and ground wires of a power source or operating electrical equipment.
Common Object Request Broker Architecture (CORBA)
An international standard for distributed computing. CORBA enables code operating on a computer to locate resources located elsewhere on the network.
companion virus
A variation of the file infector virus. A companion virus is a self-contained executable file that escapes detection by using a filename similar to, but slightly different from, a legitimate operating system file.
compartmented security mode
A security mode in which systems process two or more types of compartmented information. All system users must have an appropriate clearance to access all information processed by the system but do not necessarily need to know all the information in the system.
compensation access control
A type of access control that provides various options to other existing controls to aid in the enforcement and support of a security policy.
competent
A distinction of evidence that means that the evidence must be obtained legally. Evidence that results from an illegal search would be inadmissible because it is not competent.
compiled languages
A computer language that is converted into machine language before distribution or execution.
compliance testing
Another common usage of auditing. Verification that a system complies with laws, regulations, baselines, guidelines, standards, and policies is an important part of maintaining security in any environment.
Component Object Model (COM)
Microsoft’s standard for the use of components within a process or between processes running on the same system.
compromise
If system security has been broken, the system is considered compromised.
computer architecture
An engineering discipline concerned with the construction of computing systems from the logical level.
computer crime
Any crime that is perpetrated against or with the use of a computer.
Computer Fraud and Abuse Act
A U.S. law written to exclusively cover computer crimes that cross state boundaries to avoid infringing upon states’ rights.
Computer Security Act (CSA) of 1987
A U.S. law that mandates baseline security requirements for all federal agencies.
concentrator
See repeater.
conclusive evidence
Incontrovertible evidence that overrides all other forms of evidence.
concurrency
A security mechanism that endeavors to make certain that the information stored in a database is always correct or at least has its integrity and availability protected. Concurrency uses a “lock” feature to allow an authorized user to make changes and then “unlocks” data elements only after all changes are complete.
Confidential
A government/military classification used for data of a confidential nature. Unauthorized disclosure of confidential data will have noticeable effects and cause damage to national security. This classification is used for all data between secret and sensitive but unclassified classifications.
confidentiality
The assurance that information is protected from unauthorized disclosure and the defined level of secrecy is maintained throughout all subject-object interactions.
configuration management
The process of logging, auditing, and monitoring activities related to security controls and security mechanisms over time. This data is then used to identify agents of change, whether objects, subjects, programs, communication pathways, or even the network itself.
confinement (or confinement property)
The principle that allows a process to read from and write to certain memory locations and resources only. This is an alternate name for the * (star) Security Property of the Bell-LaPadula model.
confusion
It occurs when the relationship between the plain text and the key is complicated enough that an attacker can’t just alter the plain text and analyze the result in order to determine the key.
consistency
One of the four required characteristics of all database transactions (the other three are atomicity, isolation, and durability). All transactions must begin operating in an environment that is consistent with all of the database’s rules.
contamination
The result of mixing of data with a different classification level and/or need-to-know requirement.
content-dependent access control
A form of access control based on the contents or payload of an object.
context-dependent access control
A form of access control based on the context or surroundings of an object.
continuity
A goal an organization can accomplish by having plans and procedures to help mitigate the effects a disaster has on its continuing operations and to speed the return to normal operations.
contractual license agreement
A written contract between the software vendor and the customer outlining the responsibilities of each.
control
The use of access rules or countermeasures to limit a subject’s access to an object.
controls gap
The difference between total risk and residual risk.
Copper Distributed Data Interface (CDDI)
Deployment of FDDI using twisted-pair (in other words, copper) wires. This reduces the maximum segment length to 100 meters and is susceptible to interference.
copyright
Law that guarantees the creators of “original works of authorship” protection against the unauthorized duplication of their work.
corrective access control
An access control deployed to restore systems to normal after an unwanted or unauthorized activity has occurred. Examples of corrective access controls include alarms, mantraps, and security policies.
corrective controls
Instructions, procedures, or guidelines used to reverse the effects of an unwanted activity, such as attacks or errors.
countermeasures
Actions taken to patch a vulnerability or secure a system against an attack. Countermeasures can include altering access controls, reconfiguring security settings, installing new security devices or mechanisms, adding or removing services, and so on.
coupling
The level of interaction between objects. Lower coupling means less interaction. Lower coupling delivers better software design because objects are more independent. Lower coupling is easier to troubleshoot and update. Objects with low cohesion require lots of assistance from other objects to perform tasks and have high coupling.
covert channel
The means by which data can be communicated outside of normal, expected, or detectable methods.
covert storage channel
A channel that conveys information by writing data to a common storage area where another process can read it.
covert timing channel
A channel that conveys information by altering the performance of a system component or modifying a resource’s timing in a predictable manner.
cracker
Malicious users intent on waging an attack against a person or system. Crackers may be motivated by greed, power, or recognition. Their actions can result in stolen property (data, ideas, and so on), disabled systems, compromised security, negative public opinion, loss of market share, reduced profitability, and lost productivity.
creeping privilege(s)
When a user account accumulates privileges over time as job roles and assigned tasks change.
criminal law
Body of laws that the police and other law enforcement agencies enforce. Criminal law contains prohibitions against acts such as murder, assault, robbery, arson, theft, and similar offenses.
critical path analysis
A systematic effort to identify relationships between mission-critical applications, processes, and operations and all of the necessary supporting elements.
criticality prioritization
The prioritization of mission-critical assets and processes during the creation of BCP/DRP.
crossover error rate (CER)
The point at which the false acceptance rate (FAR) equals the false rejection rate (FRR). This is the point from which performance is measured in order to compare the capabilities of different biometric devices.
cryptanalysis
The study of methods to defeat codes and ciphers.
cryptographic key
Cryptographic keys provide the “secret” portion of a cryptographic algorithm used to encrypt and decrypt data.
cryptography
Algorithms applied to data that are designed to ensure confidentiality, integrity, authentication, and/or nonrepudiation.
cryptosystem
System in which a shared secret key or pairs of public and private keys are used by communicating parties to facilitate secure communication.
cryptovariable
Another name for the key used to perform encryption and decryption activities.
custodian
A subject that has been assigned or delegated the day-to-day responsibilities of classifying and labeling objects and properly storing and protecting objects. The custodian is typically the IT staff or the system security administrator.
cyclic redundancy check (CRC)
Similar to a hash total, a value that indicates whether a message has been altered or damaged in transit.
D
data circuit-terminating equipment (DCE)
A networking device that performs the actual transmission of data over the Frame Relay as well as establishing and maintaining the virtual circuit for the customer.
data classification
Grouping data under labels for the purpose of applying security controls and access restrictions.
data custodian
The user who is assigned the task of implementing the prescribed protection defined by the security policy and upper management. The data custodian performs any and all activities necessary to provide adequate protection for data and to fulfill the requirements and responsibilities delegated to him from upper management.
Data Definition Language (DDL)
The database programming language that allows for the creation and modification of the database’s structure (known as the schema).
data dictionary
Central repository of data elements and their relationships. Stores critical information about data usage, relationships, sources, and formats.
data diddling
The act of making small changes to data.
Data Encryption Standard (DES)
A standard cryptosystem proposed in 1977 for all government communications. DES (and 3DES) was superseded by Advanced Encryption Standard (AES) in December 2001.
data extraction
The process of extracting elements of data from a large body of data to construct a meaningful representation or summary of the whole.
data hiding
The process of preventing data from being known by a subject.
Data Link layer
Layer 2 of the OSI model.
Data Manipulation Language (DML)
The database programming language that allows users to interact with the data contained within the schema.
data mart
The storage facility used to secure metadata.
data mining
A technique or tool that allows analysts to comb through data warehouses and look for potential correlated information amid the historical data.
data owner
The person responsible for classifying information for placement and protection within the security solution.
data steward
See data custodian
data terminal equipment (DTE)
A networking device that acts like a router or a switch and provides the customer’s network access to the Frame Relay network.
data warehouse
Large databases used to store large amounts of information from a variety of databases for use in specialized analysis techniques.
database
An electronic filing system for organizing collections of information. Most databases are organized by files, records, and fields.
database management system (DBMS)
An application that enables the storage, modification, and extraction of information from a database.
database partitioning
The act of dividing a database up into smaller sections or individual databases; often employed to segregate content with varying sensitivity labels.
decentralized access control
System of access control in which authorization verification is performed by various entities located throughout a system.
decision support system (DSS)
An application that analyzes business data and presents it so as to make business decisions easier for users. DSS is considered an informational application more so than an operational application. Often a DSS is employed by knowledge workers (such as help desk or customer support) and by sales services (such as phone operators).
declassification
The process of moving a resource into a lower classification level once its value no longer justifies the security protections provided by a higher level of classification.
decrypt
The process of reversing a cryptographic algorithm that was used to encrypt a message.
dedicated mode
See dedicated security mode.
dedicated security mode
Mode in which the system is authorized to process only a specific classification level at a time. All system users must have clearance and a need to know that information.
deencapsulation
The process of stripping a layer’s header and footer from a PDU as it travels up the OSI model layers.
degaussing
The act of using a magnet to return media to its original pristine unused state.
degree
The number of columns in a relational database.
delegation
In the context of object-oriented programming, the forwarding of a request by an object to another object or delegate. An object delegates if it does not have a method to handle the message.
delta rule
Also known as the learning rule. It is the feature of expert systems that allows them to learn from experience.
Delphi technique
An anonymous feedback and response process used to arrive at a group consensus.
deluge system
Another form of dry pipe (fire suppression) system that uses larger pipes and therefore a significantly larger volume of water. Deluge systems are inappropriate for environments that contain electronics and computers.
denial of service (DoS)
A type of attack that prevents a system from processing or responding to legitimate traffic or requests for resources and objects.
deny risk
See reject risk.
detective access control
An access control deployed to discover unwanted or unauthorized activity. Examples of detective access controls include security guards, supervising users, incident investigations, and intrusion detection systems (IDSs).
detective control
See detective access control.
deterrent access control
An access control that discourages violations of a security policy.
dictionary attack
An attack against a system designed to discover the password to a known identity (in other words, a username). In a dictionary attack, a script of common passwords and dictionary words is used to attempt to discover an account’s password.
differential backup
A type of backup that stores all files that have been modified since the time of the most recent full backup.
Diffie-Hellman algorithm
A key exchange algorithm useful in situations in which two parties might need to communicate with each other but they have no physical means to exchange key material and there is no public key infrastructure in place to facilitate the exchange of secret keys.
diffusion
When a change in the plain-text results in multiple changes spread throughout the cipher text.
Digital Millennium Copyright Act
A law that establishes the prohibition of attempts to circumvent copyright protection mechanisms placed on a protected work by the copyright holder and limits the liability of Internet service providers when their circuits are used by criminals violating the copyright law.
digital signature
A method for ensuring a recipient that a message truly came from the claimed sender and that the message was not altered while in transit between the sender and recipient.
Digital Signature Standard (DSS)
A standard that specifies that all federally approved digital signature algorithms must use a secure hashing function.
direct addressing
A process by which the CPU is provided with the actual address of the memory location to be accessed.
direct evidence
Evidence that proves or disproves a specific act through oral testimony based on information gathered through the witness’s five senses.
Direct Sequence Spread Spectrum (DSSS)
A wireless technology that employs all of the available frequencies simultaneously in parallel.
directive access control
An access control that directs, confines, or controls the actions of subjects to force or encourage compliance with security policy.
detective control
Any security mechanism used to verify the effectiveness of directive and preventive controls.
directory service
A centralized database of resources available to the network, much like a telephone directory for network services and assets. Users, clients, and processes consult the directory service to learn where a desired system or resource resides.
Direct Memory Access (DMA)
A mechanism that allows devices to exchange data directly with real memory (RAM) without requiring assistance from the CPU.
disaster
An event that brings great damage, loss, or destruction to a system or environment.
disaster recovery plan
A document that guides the recovery efforts necessary to restore your business to normal operations as quickly as possible.
Disaster Recovery Planning (DRP)
Term that describes the actions an organization takes to resume normal operations after a disaster interrupts normal activity.
discretionary access control
A mechanism used to control access to objects. The owner or creator of an object controls and defines the access other subjects have to it.
Discretionary Security Property
Property that states that the system uses an access control matrix to enforce discretionary access control.
distributed access control
A form of access control in which authorization verification is performed by various entities located throughout a system.
Distributed Component Object Model (DCOM)
An extension of COM to support distributed computing. This is Microsoft’s answer to CORBA.
distributed data model
In a distributed data model, data is stored in more than one database but remains logically connected. The user perceives the database as a single entity, even though it comprises numerous parts interconnected over a network. Each field may have numerous children as well as numerous parents. Thus, the data mapping relationship is many-to-many.
distributed denial of service (DDoS)
A distributed denial of service occurs when the attacker compromises several systems to be used as launching platforms against one or more victims. The compromised systems used in the attack are often called slaves or zombies. A DDoS attack results in the victims being flooded with data from numerous sources.
distributed reflective denial of service (DRDoS)
DRDoS attacks take advantage of the normal operation mechanisms of key Internet services, such as DNS and router update protocols. DRDoS attacks function by sending numerous update, session, or control packets to various Internet service servers or routers with a spoofed source address of the intended victim. A DRDoS attack can result in so much traffic that upstream systems are adversely affected by the sheer volume of data focused on the victim.
DNS poisoning
The act of altering or falsifying the information of DNS to route or misdirect legitimate traffic.
documentary evidence
Any written items brought into court to prove a fact at hand. This type of evidence must also be authenticated.
domain
1) A realm of trust or a collection of subjects and objects that share a common security policy. Each domain’s access control is maintained independently of other domains’ access control. This results in decentralized access control when multiple domains are involved. 2) An area of study for the CISSP exam.
dry pipe system
A fire suppression system that contains compressed air. Once suppression is triggered, the air escapes, which opens a water valve that in turn causes the pipes to fill and discharge water into the environment.
due care
The steps taken to ensure that assets and employees of an organization have been secured and protected and that upper management has properly evaluated and assumed all unmitigated or transferred risks.
due diligence
The extent to which a reasonable person will endeavor under specific circumstances to avoid harming other people or property.
dumb cards
Human-readable-only card IDs that usually have a photo and written information about the authorized bearer. Dumb cards are for use in environments where automated controls are infeasible or unavailable but security guards are practical.
dumpster diving
The act of digging through the refuse, remains, or leftovers from an organization or operation in order to discover or infer information about the organization.
durability
One of the four required characteristics of all database transactions (the other three are atomicity, consistency, and isolation). The concept that database transactions must be resilient. Once a transaction is committed to the database, it must be preserved. Databases ensure durability through the use of backup mechanisms, such as transaction logs.
dwell time
The length of time a key on the keyboard is pressed. This is an element of the keystroke dynamics biometric factor.
Dynamic Host Configuration Protocol (DHCP)
A protocol used to assign TCP/IP configuration settings to systems upon bootup. DHCP uses port 67 for server point-to-point response and port 68 for client request broadcast. DHCP supports centralized control and management of network addressing.
dynamic packet-filtering firewalls
A firewall that enables real-time modification of the filtering rules based on traffic content. Dynamic packet-filtering firewalls are known as fourth-generation firewalls.
dynamic passwords
Passwords that do not remain static for an extended period of time. Dynamic passwords can change on each use or at a regular interval, such as every 30 days.
E
eavesdropping
Another term for sniffing. However, eavesdropping can include more than just capturing and recording network traffic. Eavesdropping also includes recording or listening to audio communications, faxes, radio signals, and so on.
Economic Espionage Act of 1996
A law that states that anyone found guilty of stealing trade secrets from a U.S. corporation with the intention of benefiting a foreign government or agent may be fined up to $500,000 and imprisoned for up to 15 years and that anyone found guilty of stealing trade secrets under other circumstances may be fined up to $250,000 and imprisoned for up to 10 years.
education
A detailed endeavor where students/users learn much more than they actually need to know to perform their work tasks. Education is most often associated with users pursuing certification or seeking job promotion.
El Gamal
The explanation of how the mathematical principles behind the Diffie-Hellman key exchange algorithm could be extended to support an entire public key cryptosystem used for the encryption and decryption of messages.
electronic access control (EAC)
A type of smart lock that uses a credential reader, an electromagnet, and a door-closed sensor.
electronically erasable PROM (EEPROM)
A storage system that uses electric voltages delivered to the pins of the chip to force erasure. EEPROMs can be erased without removal from the computer, giving them much greater flexibility than standard PROM and EPROM chips.
electromagnetic interference (EMI)
A type of electrical noise that can do more than just cause problems with how equipment functions; it can also interfere with the quality of communications, transmissions, and playback.
Electronic Codebook (ECB)
The simplest encryption mode to understand and the least secure. Each time the algorithm processes a 64-bit block, it simply encrypts the block using the chosen secret key. This means that if the algorithm encounters the same block multiple times, it produces the same encrypted block.
Electronic Communications Privacy Act (ECPA)
The law that makes it a crime to invade an individual’s electronic privacy. It protects against the monitoring of email and voice mail communications and prevents providers of those services from making unauthorized disclosures of their content.
electronic vaulting
A storage scenario in which database backups are transferred to a remote site in a bulk transfer fashion. The remote location may be a dedicated alternative recovery site (such as a hot site) or simply an offsite location managed within the company or by a contractor for the purpose of maintaining backup data.
elliptic curve cryptography
A new branch of public key cryptography that offers similar security to established public key cryptosystems at reduced key sizes.
elliptic curve group
Each elliptic curve has a corresponding elliptic curve group made up of the points on the elliptic curve along with the point O, located at infinity. Two points within the same elliptic curve group (P and Q) can be added together with an elliptic curve addition algorithm.
employee
Often referred to as the user when discussing IT issues. See also user.
employment agreement
A document that outlines an organization’s rules and restrictions, security policy, and acceptable use and activities policies; details the job description; outlines violations and consequences; and defines the length of time the position is to be filled by the employee.
Encapsulating Security Payload (ESP)
An element of IPSec that provides encryption to protect the confidentiality of transmitted data but can also perform limited authentication.
encapsulation
The process of adding a header and footer to a PDU as it travels down the OSI model layers.
encrypt
The process used to convert a message into cipher text.
encryption
The art and science of hiding the meaning or intent of a communication from recipients not meant to receive it.
end user
See user.
end-to-end encryption
An encryption algorithm that protects communications between two parties (in other words, a client and a server) and is performed independently of link encryption. An example of this would be the use of Privacy Enhanced Mail (PEM) to pass a message between a sender and a receiver. This protects against an intruder who might be monitoring traffic on the secure side of an encrypted link or traffic sent over an unencrypted link.
enrollment
The process of establishing a new user identity or authentication factor on a system. Secure enrollment requires physical proof of a person’s identity or authentication factor. Generally, if the enrollment process takes longer than two minutes, the identification or authorization mechanism (typically a biometric device) is not approved.
entity
A subject or an object.
erasable PROM (EPROM)
A PROM chip that has a small window through which the illumination of a special ultraviolet light causes the contents of the chip to be erased. After this process is complete, the end user can burn new information into the EPROM.
erasing
A delete operation against a file, a selection of files, or the entire media. In most cases, the deletion or erasure process removes only the directory or catalog link to the data. The actual data remains on the drive.
Escrowed Encryption Standard
A failed government attempt to create a back door to all encryption solutions. The solution employed the Clipper chip, which used the Skipjack algorithm.
espionage
The malicious act of gathering proprietary, secret, private, sensitive, or confidential information about an organization for the express purpose of disclosing and often selling that data to a competitor or other interested organization (such as a foreign government).
Ethernet
A common shared media LAN technology.
ethical hackers
Those trained in responsible network security methodology, with a philosophy toward nondestructive and nonintrusive testing, ethical hackers attack security systems on behalf of their owners seeking to identify and document vulnerabilities so that they may be remediated before malicious hackers can exploit them. Ethical hackers use the same methods to test security that unethical ones do but report what they find rather than seeking to turn them to their advantage.
ethical hacking
See penetration testing.
ethics
The rules that govern personal conduct. Several organizations have recognized the need for standard ethics rules, or codes, and have devised guidelines for ethical behavior. These rules are not laws but are minimum standards for professional behavior. They should provide you with a basis for sound, professional, ethical judgment.
evidence
In the context of computer crime, any hardware, software, or data that you can use to prove the identity and actions of an attacker in a court of law.
excessive privilege(s)
More access, privilege, or permission than a user’s assigned work tasks dictate. If a user account is discovered to have excessive privilege, the additional and unnecessary benefits should be immediately curtailed.
exit interview
An aspect of a termination policy. The terminated employee is reminded of their legal responsibilities to prevent the disclosure of confidential and sensitive information.
expert opinion
A type of evidence consisting of the opinions and facts offered by an expert. An expert is someone educated in a field and who currently works in that field.
expert system
A system that seeks to embody the accumulated knowledge of humankind on a particular subject and apply it in a consistent fashion to future decisions.
exposure
The condition of being exposed to asset loss because of a threat. Exposure involves being susceptible to the exploitation of a vulnerability by a threat agent or event.
exposure factor (EF)
The percentage of loss that an organization would experience if a specific asset were violated by a realized risk.
extranet
A cross between the Internet and an intranet. An extranet is a section of an organization’s network that has been sectioned off so that it acts as an intranet for the private network but also serves information to a limited number of specific outsiders. Often access into an extranet from the Internet requires a VPN connection. Extranets are often used in B2B applications, between customers and suppliers.
F
face scan
An example of a biometric factor, which is a behavioral or physiological characteristic that is unique to a subject. A face scan is a process by which the shape and feature layout of a person’s face is used to establish identity or provide authentication.
fail-secure
See fail-safe.
fail-safe
The response of a system to a failure so that it defaults to a “deny” posture.
fail-open
The response of a system to a failure so that it defaults to an “allow” posture.
Fair Cryptosystems
A failed government attempt to create a back door to all encryption solutions. This technology used a segmented key that was divided among several trustees.
false acceptance rate (FAR)
Error that occurs when a biometric device is not sensitive enough and an invalid subject is authenticated. Also referred to as a Type 2 error.
false rejection rate (FRR)
Error that occurs when a biometric device is too sensitive and a valid subject is not authenticated. Also referred to as a Type 1 error.
Family Educational Rights and Privacy Act (FERPA)
A specialized privacy bill that affects any educational institution that accepts any form of funding from the federal government (the vast majority of schools). It grants certain privacy rights to students older than the age of 18 and the parents of minor students.
fault
A momentary loss of power.
Federal Information Processing Standard 140 (FIPS-140)
FIPS-140 defines the hardware and software requirements for cryptographic modules that the federal government uses.
Federal Sentencing Guidelines
A 1991 law that provides punishment guidelines for breaking federal laws.
fence
A perimeter-defining device. Fences are used to clearly differentiate between areas that are under a specific level of security protection and those that are not. Fencing can include a wide range of components, materials, and construction methods.
Fiber Distributed Data Interface (FDDI)
A high-speed token-passing technology that employs two rings with traffic flowing in opposite directions. FDDI offers transmission rates of 100Mbps and is often used as a backbone to large enterprise networks.
fiber-optic
A cabling form that transmits light instead of electrical signals. Fiber-optic cable supports throughputs up to 2 Gbps and lengths of up to 2 kilometers.
file infector
Virus that infects different types of executable files and triggers when the operating system attempts to execute them. For Windows-based systems, these files end with .exe and .com extensions.
financial attack
A crime that is carried out to unlawfully obtain money or services.
fingerprints
The patterns of ridges on the fingers of humans. Often used as a biometric authentication factor.
firewall
A network device used to filter traffic. A firewall is typically deployed between a private network and a link to the Internet, but it can be deployed between departments within an organization. Firewalls filter traffic based on a defined set of rules.
firmware
Software that is stored in a ROM chip.
flight time
The length of time between key presses. This is an element of the keystroke dynamics form of biometrics.
flooding
An attack that involves sending enough traffic to a victim to cause a DoS. Also referred to as a stream attack.
Fourth Amendment
An amendment to the U.S. Constitution that prohibits government agents from searching private property without a warrant and probable cause. The courts have expanded their interpretation of the Fourth Amendment to include protections against wiretapping and other invasions of privacy.
fraggle
A form of denial-of-service attack similar to smurf, but it uses UDP packets instead of ICMP.
fragment
When a network receives a packet larger than its maximum allowable packet size, it breaks it up into two or more fragments. These fragments are each assigned a size (corresponding to the length of the fragment) and an offset (corresponding to the starting location of the fragment).
fragmentation attacks
An attack that exploits vulnerabilities in the fragment reassembly functionality of the TCP/IP protocol stack.
Frame Relay
A shared connection medium that uses packet-switching technology to establish virtual circuits for customers.
frequency analysis
A cryptographic analysis or attack that looks for repetition of letters in an encrypted message and compares that with the statistics of letter usage for a specific language, such as the frequency of the letters E, T, A, O, N, R, I, S, and H in the English language.
Frequency Hopping Spread Spectrum (FHSS)
An early implementation of the spread spectrum concept. This wireless access technology transmits data in a series while constantly changing the frequency in use.
full backup
A complete copy of data contained on the protected device on the backup media. This also refers to the process of making a complete copy of data, as in “performing a full backup.”
full-interruption tests
A disaster recovery test that involves actually shutting down operations at the primary site and shifting them to the recovery site.
full-knowledge teams
These possess a full body of knowledge over the operation, configuration, and utilization of hardware and software inventory prior to a security assessment or penetration test.
G
Gantt chart
A type of bar chart that shows the interrelationships over time between projects and schedules. It provides a graphical illustration of a schedule that helps to plan, coordinate, and track specific tasks in a project.
gate
A controlled exit and entry point in a fence.
gateway
A networking device that connects networks that are using different network protocols.
Government Information Security Reform Act of 2000
Act that amends the United States Code to implement additional information security policies and procedures.
government/military classification
The security labels commonly employed on secure systems used by the military. Military security labels range from highest sensitivity to lowest: top secret, secret, confidential, sensitive but unclassified, and unclassified (top secret, secret, and confidential are collectively known as classified).
Gramm-Leach-Bliley (GLBA) Act
A law passed in 1999 that eased the strict governmental barriers between financial institutions. Banks, insurance companies, and credit providers were severely limited in the services they could provide and the information they could share with each other. GLBA somewhat relaxed the regulations concerning the services each organization could provide.
granular object control
A very specific and highly detailed level of control over the security settings of an object.
ground
The wire in an electrical circuit that is grounded (that is, connected with the earth).
group
An access control management simplification mechanism similar to a role. Similar users are made members of a group. A group is assigned access to an object. Thus, all members of the group are granted the same access to an object. The use of groups greatly simplifies the administrative overhead of managing user access to objects.
grudge attack
Attack usually motivated by a feeling of resentment and carried out to damage an organization or a person. The damage could be in the loss of information or harm to the organization or a person’s reputation. Often the attacker is a current or former employee or someone who wishes ill will upon an organization.
guideline
A document that offers recommendations on how standards and baselines are implemented. Guidelines outline methodologies, include suggested actions, and are not compulsory.
H
hacker
A technology enthusiast who does not have malicious intent. Many authors and the media often use the term when they are actually discussing issues relating to crackers.
Halon
A fire-suppressant material that converts to toxic gases at 900 degrees Fahrenheit and depletes the ozone layer of the atmosphere and is therefore usually replaced by an alternative material.
hand geometry
A type of biometric control that recognizes the physical dimensions of a hand. This includes width and length of the palm and fingers. It can be a mechanical or image-edge (in other words, visual silhouette) graphical solution.
handshaking
A three-way process utilized by the TCP/IP protocol stack to set up connections between two hosts.
hardware
An actual physical device, such as a hard drive, LAN card, printer, and so on.
hardware segmentation
A technique that implements process isolation at the hardware level by enforcing memory access constraints.
hash
A number known as a message digest generated from a hash function. Also see hash function.
hash function
The process of taking a full message and generating a unique output value derived from the content of the message. This value is commonly referred to as the message digest.
hash total
A checksum used to verify the integrity of a transmission. See also cyclic redundancy check (CRC).
hash value
A number that is generated from a string of text and is substantially smaller than the text itself. A formula creates a hash value in a way that it is extremely unlikely that any other text will produce the same hash value.
Hashed Message Authentication Code (HMAC)
An algorithm that implements a partial digital signature—it guarantees the integrity of a message during transmission, but it does not provide for nonrepudiation.
Health Insurance Portability and Accountability Act (HIPAA)
A law passed in 1996 that made numerous changes to the laws governing health insurance and health maintenance organizations (HMOs). Among the provisions of HIPAA are privacy regulations requiring strict security measures for hospitals, physicians, insurance companies, and other organizations that process or store private medical information about individuals.
hearsay evidence
Evidence consisting of statements made to a witness by someone else outside of court. Computer log files that are not authenticated by a system administrator can also be considered hearsay evidence.
heart/pulse pattern
An example of a biometric factor, which is a behavioral or physiological characteristic that is unique to a subject. The heart/pulse pattern of a person is used to establish identity or provide authentication.
heuristics-based detection
See behavior-based detection.
hierarchical
A form of MAC environment. Hierarchical environments relate the various classification labels in an ordered structure from low security to medium security to high security. Each level or classification label in the structure is related. Clearance in a level grants the subject access to objects in that level as well as to all objects in all lower levels but prohibits access to all objects in higher levels.
hierarchical data model
A form of database that combines records and fields that are related in a logical tree structure. This is done so that each field can have one child or many or no children but each field can have only a single parent. Therefore, the data mapping relationship is one-to-many.
High-Speed Serial Interface (HSSI)
A layer 1 protocol used to connect routers and multiplexers to ATM or Frame Relay connection devices.
High-Level Data Link Control (HDLC)
A layer 2 protocol used to transmit data over synchronous communication lines. HDLC is an ISO standard based on IBM’s SDLC. HDLC supports full-duplex communications, supports both point-to-point and multipoint connections, offers flow control, and includes error detection and correction.
high-level languages
Programming languages that are not machine languages or assembly languages. These languages are not hardware dependent and are more understandable by humans. Such languages must be converted to machine language before or during execution.
hijack attack
An attack in which a malicious user is positioned between a client and server and then interrupts the session and takes it over. Often, the malicious user impersonates the client so they can extract data from the server. The server is unaware that any change in the communication partner has occurred.
honey pot
Individual computers or entire networks created to serve as a snare for intruders. The honey pot looks and acts like a legitimate network, but it is 100 percent fake. Honey pots tempt intruders with unpatched and unprotected security vulnerabilities as well as hosting attractive, tantalizing, but faux data. Honey pots are designed to grab an intruder’s attention and direct them into the restricted playground while keeping them away from the legitimate network and confidential resources.
host-based IDS
An intrusion detection system (IDS) that is installed on a single computer and can monitor the activities on that computer. A host-based IDS is able to pinpoint the files and processes compromised or employed by a malicious user to perform unauthorized activity.
hostile applet
Any piece of mobile code that attempts to perform unwanted or malicious activities.
hot site
A configuration in which a backup facility is maintained in constant working order, with a full complement of servers, workstations, and communications links ready to assume primary operations responsibilities.
hub
A network device used to connect multiple systems together in a star topology. Hubs repeat inbound traffic over all outbound ports.
hybrid
A type of MAC environment. A hybrid environment combines the hierarchical and compartmentalized concepts so that each hierarchical level can contain numerous subcompartments that are isolated from the rest of the security domain. A subject must have not only the correct clearance but also the need-to-know for the specific compartment in order to have access to the compartmentalized object.
hybrid attack
A form of password attack in which a dictionary attack is first attempted and then a type of brute-force attack is performed. The follow-up brute-force attack is used to add prefix or suffix characters to passwords from the dictionary in order to discover one-upped constructed passwords, two-upped constructed passwords, and so on.
Hypertext Transfer Protocol
The protocol used to transmit web page elements from a web server to web browsers (over the well-known service TCP/UDP port address 80).
Hypertext Transfer Protocol over Secure Sockets Layer (HTTPS)
A standard that uses port 443 to negotiate encrypted communications sessions between web servers and browser clients.
I
identification
The process by which a subject professes an identity and accountability is initiated. The identification process can consist of a user providing a username, a logon ID, a PIN, or a smart card or a process providing a process ID number.
identification card
A form of physical identification; generally contains a picture of the subject and/or a magnetic strip with additional information about a subject.
Identity Theft and Assumption Deterrence Act
An act that makes identity theft a crime against the person whose identity was stolen and provides severe criminal penalties (up to a 15-year prison term and/or a $250,000 fine) for anyone found guilty of violating it.
ignore risk
Denying that a risk exists and hoping that by ignoring a risk it will never be realized.
immediate addressing
A way of referring to data that is supplied to the CPU as part of an instruction.
impersonation
The assumption of someone’s identity or online account, usually through the mechanisms of spoofing and session replay. An impersonation attack is considered a more active attack than masquerading.
implementation attack
This type of attack exploits weaknesses in the implementation of a cryptography system. It focuses on exploiting the software code, not just errors and flaws but methodology employed to program the encryption system.
inappropriate activities
Actions that may take place on a computer or over the IT infrastructure and that may not be actual crimes but are often grounds for internal punishments or termination. Some types of inappropriate activities include viewing inappropriate content, sexual and racial harassment, waste, and abuse.
incident
The occurrence of a system intrusion.
incremental backups
A backup that stores only those files that have been modified since the time of the most recent full or incremental backup. This is also used to mean the process of creating such a backup.
indirect addressing
The memory address that is supplied to the CPU as part of the instruction and doesn’t contain the actual value that the CPU is to use as an operand. Instead, the memory address contains another memory address (perhaps located on a different page). The CPU then retrieves the actual operand from that address.
industrial espionage
The act of someone using illegal means to acquire competitive information.
inference
An attack that involves using a combination of several pieces of nonsensitive information to gain access to information that should be classified at a higher level.
inference engine
The second major component of an expert system that analyzes information in the knowledge base to arrive at the appropriate decision.
information flow model
A model that focuses on the flow of information to ensure that security is maintained and enforced no matter how information flows. Information flow models are based on a state machine model.
information hiding
Placing data and a subject at different security domains for the purpose of hiding the data from that subject.
informative policy
A policy that is designed to provide information or knowledge about a specific subject, such as company goals, mission statements, or how the organization interacts with partners and customers. An informative policy is nonenforceable.
inherit (or inheritance)
In object-oriented programming, inheritance refers to a class having one or more of the same methods from another class. So when a method has one or more of the same methods from another class, it is said to have “inherited” them.
initialization vector (IV)
A nonce used by numerous cryptography solutions to increase the strength of encrypted data by increasing the randomness of the input.
inrush
An initial surge of power usually associated with connecting to a power source, whether primary or alternate/secondary.
instance
In object-oriented programming, an instance can be an object, example, or representation of a class.
Integrated Services Digital Network (ISDN)
A digital end-to-end communications mechanism. ISDN was developed by telephone companies to support high-speed digital communications over the same equipment and infrastructure that is used to carry voice communications.
integrity
A state characterized by the assurance that modifications are not made by unauthorized users and authorized users do not make unauthorized modifications.
intellectual property
Intangible assets, such as secret recipes or production techniques.
International Data Encryption Algorithm (IDEA)
A block cipher that was developed in response to complaints about the insufficient key length of the DES algorithm. IDEA operates on 64-bit blocks of plain/cipher text, but it begins its operation with a 128-bit key.
International Organization for Standardization (ISO)
An independent oversight organization that defines and maintains computer, networking, and technology standards, along with more than 13,000 other international standards for business, government, and society.
Internet Key Exchange (IKE)
A protocol that provides for the secure exchange of cryptographic keys between IPSec participants.
Internet Message Access Protocol (IMAP)
A protocol used to transfer email messages from an email server to an email client.
Internet Security Association and Key Management Protocol (ISAKMP)
A protocol that provides background security support services for IPSec.
interpreted languages
Programming languages that are converted to machine language one command at a time at the time of execution.
interrupt (IRQ)
A mechanism used by devices and components in a computer to get the attention of the CPU.
intranet
A private network that is designed to host the same information services found on the Internet.
intrusion
The condition in which a threat agent has gained access to an organization’s infrastructure through the circumvention of security controls and is able to directly imperil assets. Also referred to as penetration.
intrusion detection
A specific form of monitoring both recorded information and real-time events to detect unwanted system access.
intrusion detection system (IDS)
A product that automates the inspection of audit logs and real-time system events. IDSs are generally used to detect intrusion attempts, but they can also be employed to detect system failures or rate overall performance.
IP header protocol field value
An element in an IP packet header that identifies the protocol used in the IP packet payload (usually this will be 6 for TCP, 17 for UDP, or 1 for ICMP, or any of a number of other valid routing protocol numbers).
IP Payload Compression (IPcomp) protocol
A protocol that allows IPSec users to achieve enhanced performance by compression packets prior to the encryption operation.
IP probes
An attack technique that uses automated tools to ping each address in a range. Systems that respond to the ping request are logged for further analysis. Addresses that do not produce a response are assumed to be unused and are ignored.
IP Security (IPSec)
A standards-based mechanism for providing encryption for point-to-point TCP/IP traffic.
IP spoofing
The process by which a malicious individual reconfigures their system so that it has the IP address of a trusted system and then attempts to gain access to other external resources.
iris scans
An example of a biometric factor, which is a behavioral or physiological characteristic that is unique to a subject. The colored portion of the eye that surrounds the pupil is used to establish identity or provide authentication.
isolation
A concept that ensures that any behavior will affect only the memory and resources associated with the process.
J
Java
A platform-independent programming language developed by Sun Microsystems.
job description
A detailed document outlining a specific position needed by an organization. A job description includes information about security classification, work tasks, and so on.
job responsibilities
The specific work tasks an employee is required to perform on a regular basis.
job rotation
A means by which an organization improves its overall security by rotating employees among numerous job positions. Job rotation serves two functions. First, it provides a type of knowledge redundancy. Second, moving personnel around reduces the risk of fraud, data modification, theft, sabotage, and misuse of information.
K
Kerchoff’s assumption
The idea that all algorithms should be public but all keys should remain private. Kerchoff’s assumption is held by a large number of cryptologists, but not all of them.
Kerberos
A ticket-based authentication mechanism that employs a trusted third party to provide identification and authentication.
kernel
The part of an operating system that always remains resident in memory (so that it can run on demand at any time).
kernel proxy firewalls
A firewall that is integrated into an operating system’s core to provide multiple levels of session and packet evaluation. Kernel proxy firewalls are known as fifth-generation firewalls.
key
A secret value used to encrypt or decrypt messages.
key distribution center (KDC)
An element of the Kerberos authentication system. The KDC maintains all the secret keys of enrolled subjects and objects. A KDC is also a COMSEC facility that distributes symmetric crypto keys, especially for government entities.
key escrow system
A cryptographic recovery mechanism by which keys are stored in a database and can be recovered only by authorized key escrow agents in the event of key loss or damage.
keystroke dynamics
A biometric factor that measures how a subject uses a keyboard by analyzing flight time and dwell time.
keystroke monitoring
The act of recording the keystrokes a user performs on a physical keyboard. The act of recording can be visual (such as with a video recorder) or logical/technical (such as with a capturing hardware device or a software program).
keystroke patterns
An example of a biometric factor, which is a behavioral or physiological characteristic that is unique to a subject. The pattern and speed of a person typing a passphrase is used to establish identity or provide authentication.
knowledge base
A component of an expert system, the knowledge base contains the rules known by an expert system and seeks to codify the knowledge of human experts in a series of “if/then” statements.
knowledge-based detection
An intrusion discovery mechanism used by IDS and based on a database of known attack signatures. The primary drawback to a knowledge-based IDS is that it is effective only against known attack methods.
known plain-text attack
An attack in which the attacker has a copy of the encrypted message along with the plain-text message used to generate the cipher text (the copy). This greatly assists the attacker in breaking weaker codes.
KryptoKnight
A ticket-based authentication mechanism similar to Kerberos but based on peer-to-peer authentication.
L
LAN extender
A remote access, multilayer switch used to connect distant networks over WAN links. This is a strange beast of a device in that it creates WANs but marketers of this device steer clear of the term WAN and use only the terms LAN and extended LAN. The idea behind this device was to make the terminology easier to understand and thus make the device easier to sell than a more conventional WAN device grounded in complex concepts and terms.
land attack
A type of DoS. A land attack occurs when the attacker sends numerous SYN packets to a victim and the SYN packets have been spoofed to use the same source and destination IP address and port number as the victim’s. This causes the victim to think it sent a TCP/IP session opening packet to itself, which causes a system failure, usually resulting in a freeze, crash, or reboot.
lattice-based access control
A variation of nondiscretionary access controls. Lattice-based access controls define upper and lower bounds of access for every relationship between a subject and object. These boundaries can be arbitrary, but they usually follow the military or corporate security label levels.
layer 1
The Physical layer of the OSI model.
layer 2
The Data Link layer of the OSI model.
layer 3
The Network layer of the OSI model.
layer 4
The Transport layer of the OSI model.
layer 5
The Session layer of the OSI model.
layer 6
The Presentation layer of the OSI model.
layer 7
The Application layer of the OSI model.
Layer 2 Forwarding (L2F)
A protocol developed by Cisco as a mutual authentication tunneling mechanism. L2F does not offer encryption.
Layer 2 Tunneling Protocol (L2TP)
A point-to-point tunnel protocol developed by combining elements from PPTP and L2F. L2TP lacks a built-in encryption scheme but typically relies upon IPSec as its security mechanism.
layering
The use of multiple security controls in series to provide for maximum effectiveness of security deployment.
learning rule
See delta rule.
licensing
A contract that states how a product is to be used.
lighting
One of the most commonly used forms of perimeter security control. The primary purpose of lighting is to discourage casual intruders, trespassers, prowlers, and would-be thieves who would rather perform their malicious activities in the dark.
link encryption
An encryption technique that protects entire communications circuits by creating a secure tunnel between two points. This is done by using either a hardware or software solution that encrypts all traffic entering one end of the tunnel and decrypts all traffic exiting the other end of the tunnel.
local alarm systems
Alarm systems that broadcast an audible signal that can be easily heard up to 400 feet away. Additionally, local alarm systems must be protected from tampering and disablement, usually by security guards. In order for a local alarm system to be effective, there must be a security team or guards positioned nearby who can respond when the alarm is triggered.
local area network (LAN)
A network that is geographically limited, such as within a single office, building, or city block.
log analysis
A detailed and systematic form of monitoring. The logged information is analyzed in detail to look for trends and patterns as well as abnormal, unauthorized, illegal, and policy-violating activities.
logging
The activity of recording information about events or occurrences to a log file or database.
logic bomb
Malicious code objects that infect a system and lie dormant until they are triggered by the occurrence of one or more conditions.
logical access control
A hardware or software mechanism used to manage access to resources and systems and provide protection for them. They are the same as technical access controls. Examples of logical or technical access controls include encryption, smart cards, passwords, biometrics, constrained interfaces, access control lists, protocols, firewalls, routers, intrusion detection systems, and clipping levels.
logon credentials
The identity and the authentication factors offered by a subject to establish access.
logon script
A script that runs at the moment of user logon. A logon script is often used to map local drive letters to network shares, to launch programs, or to open links to often accessed systems.
loopback address
The IP address used to create a software interface that connects to itself via the TCP/IP protocol. The loopback address is handled by software alone. It permits testing of the TCP/IP protocol stack even if network interfaces or their device drivers are missing or damaged.
Low Water-Mark Mandatory Access Control (LOMAC)
A loadable kernel module for Linux designed to protect the integrity of processes and data. It is an OS security architecture extension or enhancement that provides flexible support for security policies.
M
machine language
A programming language that can be directly executed by a computer.
macro viruses
A virus that utilizes crude technologies to infect documents created in the Microsoft Word environment.
mail-bombing
An attack in which sufficient numbers of messages are directed to a single user’s inbox or through a specific STMP server to cause a denial of service.
maintenance
The variety of tasks that are necessary to ensure continued operation in the face of changing operational, data processing, storage, and environmental requirements.
maintenance hooks
Entry points into a system that only the developer of the system knows; also called back doors.
malicious code
Code objects that include a broad range of programmed computer security threats that exploit various network, operating system, software, and physical security vulnerabilities to spread malicious payloads to computer systems.
mandatory access control
An access control mechanism that uses security labels to regulate subject access to objects.
mandatory vacations
A security policy that requires all employees to take vacations annually so their work tasks and privileges can be audited and verified. This often results in easy detection of abuse, fraud, or negligence.
man-in-the-middle attack
A type of attack that occurs when malicious users are able to position themselves between the two endpoints of a communication’s link. The client and server are unaware that there is a third party intercepting and facilitating their communication session.
man-made disasters
Disasters cause by humans, including explosions, electrical fires, terrorist acts, power outages, utility failures, hardware/software failures, labor difficulties, theft, and vandalism.
mantrap
A double set of doors that is often protected by a guard. The purpose of a mantrap is to contain a subject until their identity and authentication is verified.
masquerading
Using someone else’s security ID to gain entry into a facility or system.
massively parallel processing (MPP)
Technology used to create systems that house hundreds or even thousands of processors, each of which has its own operating system and memory/bus resources.
master boot record (MBR)
The portion of a hard drive or floppy disk that the computer uses to load the operating system during the boot process.
master boot record (MBR) virus
Virus that attacks the MBR. When the system reads the infected MBR, the virus instructs it to read and execute the code stored in an alternate location, thereby loading the entire virus into memory and potentially triggering the delivery of the virus’s payload.
maximum tolerable downtime (MTD)
The maximum length of time a business function can be inoperable without causing irreparable harm to the business.
MD2 (Message Digest 2)
A hash algorithm developed by Ronald Rivest in 1989 to provide a secure hash function for 8-bit processors.
MD4
An enhanced version of the MD2 algorithm, released in 1990. MD4 pads the message to ensure that the message length is 64 bits smaller than a multiple of 512 bits.
MD5
The next version the MD algorithm, released in 1991, which processes 512-bit blocks of the message, but it uses four distinct rounds of computation to produce a digest of the same length as the MD2 and MD4 algorithms (128 bits).
mean time to failure (MTTF)
The length of time or number of uses a hardware or media component can endure before its reliability is questionable and it should be replaced.
Media Access Control (MAC) address
A 6-byte address written in hexadecimal. The first three bytes of the address indicate the vendor or manufacturer of the physical network interface. The last three bytes make up a unique number assigned to that interface by the manufacturer. No two devices on the same network can have the same MAC address.
meet-in-the-middle attack
An attack in which the attacker uses a known plain-text message. The plain text is then encrypted using every possible key (k1), while the equivalent cipher text is decrypted using all possible keys (k2).
memory
The main memory resources directly available to a system’s CPU. Primary memory normally consists of volatile random access memory (RAM) and is usually the most high-performance storage resource available to a system.
memory card
A device that can store data but cannot process it; often built around some form of flash memory.
memory page
A single chunk of memory that can be moved to and from RAM and the paging file on a hard drive as part of a virtual memory system.
memory-mapped I/O
A technique used to manage input/output between system components and the CPU.
message
The communications to or input for an object (in the context of object-oriented programming terminology and concepts).
message digest (MD)
A summary of a message’s content (not unlike a file checksum) produced by a hashing algorithm.
metadata
The results of a data mining operation on a data warehouse.
metamodel
A model of models. Because the spiral model encapsulates a number of iterations of another model (the waterfall model), it is known as a metamodel.
methods
The actions or functions performed on input (messages) to produce output (behaviors) by objects in an object-oriented programming environment.
microcode
A term used to describe software that is stored in a ROM chip. Also called firmware.
middle management
See security professional.
military and intelligence attacks
Attacks that are launched primarily to obtain secret and restricted information from law enforcement or military and technological research sources.
MIME Object Security Services (MOSS)
Standard that provides authenticity, confidentiality, integrity, and nonrepudiation for email messages.
mitigated
The process by which a risk is reduced or removed.
mitigate risk
See reducing risk.
mobile sites
Nonmainstream alternatives to traditional recovery sites that typically consist of self-contained trailers or other easily relocated units.
module testing
When each independent or self-contained segment of code for which there exists a distinct and separate specification is tested independently of all other modules. This can also be called component testing. This can be seen as a parent or superclass of unit testing.
modulo
The remainder value left over after a division operation is performed.
MONDEX
A type of electronic payment system and protocol designed to manage cash on smart cards.
monitoring
The activity of manually or programmatically reviewing logged information looking for specific information.
motion detector
A device that senses the occurrence of motion in a specific area.
motion sensor
See motion detector.
multicast
A communications transmission to multiple identified recipients.
multilevel mode
See multilevel security mode.
multilevel security mode
A system that is authorized to process information at more than one level of security even when all system users do not have appropriate clearances or a need to know for all information processed by the system.
multipartite virus
A virus that uses more than one propagation technique in an attempt to penetrate systems that defend against only one method or the other.
multiprocessing
A technology that makes it possible for a computing system to harness the power of more than one processor to complete the execution of a single application.
multiprogramming
The pseudo-simultaneous execution of two tasks on a single processor coordinated by the operating system for the purpose of increasing operational efficiency. Multiprogramming is considered a relatively obsolete technology and is rarely found in use today except in legacy systems.
multistate
Term used to describe a system that is certified to handle multiple security levels simultaneously by using specialized security mechanisms that are designed to prevent information from crossing between security levels.
multitasking
A system handling two or more tasks simultaneously.
multithreading
A process that allows multiple users to use the same process without interfering with each other.
mutual assistance agreement (MAA)
An agreement in which two organizations pledge to assist each other in the event of a disaster by sharing computing facilities or other technological resources.
N
natural disaster
A disaster that is not caused by man, such as earthquakes, mud slides, sink holes, fires, floods, hurricanes, tornadoes, falling rocks, snow, rainfall, ice, humidity, heat, extreme cold, and so on.
need-to-know
The requirement to have access to, knowledge about, or possession of data or a resource in order to perform specific work tasks. A user must have a need to know in order to gain access to data or resources. Even if that user has an equal or greater security classification than the requested information, if they do not have a need to know, they are denied access.
negligence
Failure to exercise the degree of care considered reasonable under the circumstances, resulting in an unintended injury to another party.
Network Address Translation (NAT)
A mechanism for converting the internal private IP addresses found in packet headers into public IP addresses for transmission over the Internet.
Network layer
Layer 3 of the OSI model.
network-based IDS
An IDS installed onto a host to monitor a network. Network-based IDSs detect attacks or event anomalies through the capture and evaluation of network packets.
neural network
A system in which a long chain of computational decisions that feed into each other and eventually add up to produce the desired output is set up.
noise
A steady interfering disturbance.
nonce
A random number generator variable used in cryptography software and creates a new and unique value every time it is used often based on a timestamp based seed value.
nondisclosure agreement (NDA)
A document used to protect the confidential information within an organization from being disclosed by a former employee. When a person signs an NDA, they agree not to disclose any information that is defined as confidential to anyone outside of the organization. Often, violations of an NDA are met with strict penalties.
nondiscretionary access control
An access control mechanism that regulates subject access to objects by using roles or tasks.
noninterference model
A model loosely based on the information flow model. The noninterference model is concerned with the actions of one subject affecting the system state or actions of another subject.
nonrepudiation
A feature of a security control or an application that prevents the sender of a message or the subject of an activity or event from denying that the event occurred.
nonvolatile
See nonvolatile storage.
nonvolatile storage
A storage system that does not depend upon the presence of power to maintain its contents, such as magnetic/optical media and nonvolatile RAM (NVRAM).
normalization
The database process that removes redundant data and ensures that all attributes are dependent on the primary key.
NOT
An operation (represented by the ~ or ! symbol) that reverses the value of an input variable. This function operates on only one variable at a time.
O
object
A passive entity that provides information or data to subjects. An object can be a file, a database, a computer, a program, a process, a file, a printer, a storage media, and so on.
object linking and embedding (OLE)
A Microsoft technology used to link data objects into or from multiple files or sources on a computer.
object-oriented programming (OOP)
A method of programming that uses encapsulated code sets called objects. OOP is best suited for eliminating error propagation and mimicking or modeling the real world.
object-relational database
A relational database combined with an object-oriented programming environment.
one-time pad
An extremely powerful type of substitution cipher that uses a different key for each message. The key length is the same length as the message.
one-time password
A variant of dynamic passwords that is changed every time it is used.
one-upped constructed password
A password with a single-character difference from its present form in a dictionary list.
one-way encryption
A mathematical function performed on passwords, messages, CRCs, and so on, that creates a cryptographic code that cannot be reversed.
one-way function
A mathematical operation that easily produces output values for each possible combination of inputs but makes it impossible to retrieve the input values. Public key cryptosystems are all based upon some sort of one-way function.
open system authentication (OSA)
A connection scheme for wireless networks where no real authentication is required, as long as a radio signal can be transmitted between the client and WAP, then communications are allowed.
Open Systems Interconnection (OSI) model
A standard model developed to establish a common communication structure or standard for all computer systems.
operational plans
Short-term and highly detailed plans based on the strategic and tactical plans. Operational plans are valid or useful only for a short time. They must be updated often (such as monthly or quarterly) to retain compliance with tactical plans. Operational plans are detailed plans on how to accomplish the various goals of the organization.
operations security triple
The relationship between asset, vulnerability, and threat.
OR
An operation (represented by the ∨ symbol) that checks to see whether at least one of the input values is true.
organizational owner
See senior management.
Orthogonal Frequency-Division Multiplexing (OFDM)
A wireless technology that employs a digital multicarrier modulation scheme that allows for a more tightly compacted transmission.
OSI model
See Open Systems Interconnection (OSI) model.
Output Feedback (OFB)
A mode in which DES XORs plain text with a seed value. For the first encrypted block, an initialization vector is used to create the seed value. Future seed values are derived by running the DES algorithm on the preceding seed value. The major advantage of OFB mode is that transmission errors do not propagate to affect the decryption of future blocks.
overt channel
An obvious, visible, detectable, known method of communicating that is addressed by a security policy and subsequently controlled by logical or technical access controls.
overwriting
See clearing.
owner
The person who has final corporate responsibility for the protection and storage of data. The owner may be liable for negligence if they fail to perform due diligence in establishing and enforcing security policy to protect and sustain sensitive data. The owner is typically the CEO, president, or department head.
P
package
In the context of the Common Criteria for information technology security evaluation, a package is a set of security features that can be added or removed from a target system.
packet
A portion of a message that contains data and the destination address; also called a datagram.
padded cell
Similar to a honey pot. When an intruder is detected by an IDS, the intruder is transferred to a padded cell. The padded cell has the look and layout of the actual network, but within the padded cell the intruder can neither perform malicious activities nor access any confidential data. A padded cell is a simulated environment that may offer fake data to retain an intruder’s interest.
palm geography
An example of a biometric factor, which is a behavioral or physiological characteristic that is unique to a subject. The shape of a person’s hand is used to establish identity or provide authentication.
palm scan
See palm topography.
palm topography
An example of a biometric factor, which is a behavioral or physiological characteristic that is unique to a subject. The layout of ridges, creases, and grooves on a person’s palm is used to establish identity or provide authentication. This is the same as a palm scan and similar to a fingerprint.
parallel run
A type of new system deployment testing in which the new system and the old system are run in parallel.
parallel tests
Testing that involves actually relocating personnel to an alternate recovery site and implementing site activation procedures.
parole evidence rule
An rule that states that when an agreement between parties is put into written form, the written document is assumed to contain all the terms of the agreement and no verbal agreements may modify the written agreement.
partial-knowledge teams
Possess a detailed account of organizational assets, including hardware and software inventory, prior to a penetration test.
passphrase
A string of characters usually much longer than a password. Once the passphrase is entered, the system converts it into a virtual password for use by the authentication process. Passphrases are often natural-language sentences to allow for simplified memorization.
password
A string of characters entered by a subject as an authentication factor.
Password Authentication Protocol (PAP)
A standardized authentication protocol for PPP. PAP transmits usernames and passwords in the clear. PAP offers no form of encryption; it simply provides a means to transport the logon credentials from the client to the authentication server.
password policy
The section of an organization’s security policy that dictates the rules, restrictions, and requirements of passwords. This can also indicate the programmatic controls deployed on a system to improve the strength of passwords.
password restrictions
The rules that define the minimal requirements of passwords, such as length, character composition, and age.
patent
A governmental grant that bestows upon an invention’s creator the sole right to make, use, and sell that invention for a set period of time.
pattern-matching detection
See knowledge-based detection.
penetration
See intrusion.
penetration testing
An activity used to test the strength and effectiveness of deployed security measures with an authorized attempted intrusion attack. Penetration testing should be performed only with the consent and knowledge of the management staff.
permanent virtual circuit (PVC)
A predefined virtual circuit that is always available for a Frame Relay customer.
personal identification number (PIN)
A number or code assigned to a person to be used as an identification factor. PINs should be kept secret.
personnel management
An important factor in maintaining operations security. Personnel management is a form of administrative control or administrative management.
phone phreaking
The process of breaking into telephone company computers to place free calls.
physical access control
A physical barrier deployed to prevent direct contact with systems. Examples of physical access controls include guards, fences, motion detectors, locked doors, sealed windows, lights, cable protection, laptop locks, swipe cards, dogs, CCTV, mantraps, and alarms.
physical controls for physical security
See physical access control.
Physical layer
Layer 1 of the OSI model.
piggybacking
The act of following someone through a secured gate or doorway without being identified or authorized personally.
ping
A utility used to troubleshoot a connection to test whether a particular IP address is accessible.
ping-of-death attack
A type of DoS. A ping-of-death attack employs an oversized ping packet. Using special tools, an attacker can send numerous oversized ping packets to a victim. In many cases, when the victimized system attempts to process the packets, an error occurs causing the system to freeze, crash, or reboot.
plain old telephone service (POTS)
Normal telephone service.
plaintext
A message that has not been encrypted.
playback attack
See replay attack.
Point-to-Point Protocol (PPP)
A full-duplex protocol used for the transmission of TCP/IP packets over various non-LAN connections, such as modems, ISDN, VPNs, Frame Relay, and so on. PPP is widely supported and is the transport protocol of choice for dial-up Internet connections.
Point-to-Point Tunneling Protocol (PPTP)
An enhancement of PPP that creates encrypted tunnels between communication endpoints. PPTP is used on VPNs but is often replaced by L2TP.
policy
See security policy.
polyalphabetic substitution
A cryptographic transformation that encrypts a message using letter-by-letter conversion and multiple alphabets from different languages or countries.
polyinstantiation
The event that occurs when two or more rows in the same table appear to have identical primary key elements but contain different data for use at differing classification levels. Polyinstantiation is often used as a defense against some types of inference attacks.
polymorphic virus
A virus that modifies its own code as it travels from system to system. The virus’s propagation and destruction techniques remain the same, but the signature of the virus is somewhat different each time it infects a new system.
polymorphism
In the context of object-oriented programming terminology and concepts, the characteristic of an object to provide different behaviors based upon the same message and methods owing to variances in external conditions.
port
A connection address within a protocol.
Port Address Translation (PAT)
A mechanism for converting the internal private IP addresses found in packet headers into public IP addresses and port numbers for transmission over the Internet. PAT supports a many-to-one mapping of internal to external IP addresses by using ports.
port scan
Software used by an intruder to probe all of the active systems on a network and determine what public services are running on each machine.
postmortem review
An analysis and review of an activity after its completion to determine its success and whether processes and procedures need to be improved.
Post Office Protocol (POP)
A protocol used to transfer email messages from an email server to an email client.
preaction system
A combination dry pipe/wet pipe system. The system exists as a dry pipe until the initial stages of a fire (smoke, heat, and so on) are detected and then the pipes are filled with water. The water is released only after the sprinkler head activation triggers are melted by sufficient heat. If the fire is quenched before the sprinklers are triggered, the pipes can be manually emptied and reset. This also allows for manual intervention to stop the release of water before sprinkler triggering occurs. Preaction systems are the most appropriate water-based system for environments that include both computers and humans in the same locations.
Presentation layer
Layer 6 of the OSI model.
Pretty Good Privacy (PGP)
A public/private key system that uses the IDEA algorithm to encrypt files and email messages. PGP is not a standard but rather an independently developed product that has wide Internet grassroots support.
preventative access control
See preventive access control.
preventive access control
An access control deployed to stop an unwanted or unauthorized activity from occurring. Examples of preventive access controls include fences, security policies, security awareness training, and antivirus software.
preventive control
Any security mechanism, tool, or practice that can deter and mitigate undesirable actions or events.
primary memory
Storage that normally consists of volatile random access memory (RAM) and is usually the most high-performance storage resource available to a system.
Primary Rate Interface (PRI)
An ISDN service type that provides up to 23 B channels and one D channel. Thus, a full PRI ISDN connection offers 1.544 Mbps throughput, the same as a T1 line.
primary storage
The RAM that a computer uses to keep necessary information readily available.
principle of least privilege
An access control philosophy that states that subjects are granted the minimal access possible for the completion of their work tasks.
privacy
An element of confidentiality aimed at preventing personal or sensitive information about an individual or organization from being disclosed.
Privacy Act of 1974
A law that mandates that government agencies maintain only records that are necessary for the conduct of their business and destroy those records when they are no longer needed for a legitimate function of government. It provides a formal procedure for individuals to gain access to records the government maintains about them and to request that incorrect records be amended. The Privacy Act also restricts the way the federal government can deal with private information about individual citizens.
Privacy Enhanced Mail (PEM)
An email encryption mechanism that provides authentication, integrity, confidentiality, and nonrepudiation. PEM is a layer 7 protocol. PEM uses RSA, DES, and X.509.
private
A commercial business/private sector classification used for data of a private or personal nature that is intended for internal use only. A significant negative impact could occur for the company or individuals if private data is disclosed.
private branch exchange (PBX)
A sophisticated telephone system often used by organizations to provide inbound call support, extension-to-extension calling, conference calling, and voicemail. This can be implemented as a stand-alone phone system network or can be integrated with the IT infrastructure.
private IP addresses
The addresses defined in RFC 1918, which are not routed over the Internet.
private key
A secret value that is used to encrypt or decrypt messages and is kept secret and known only to the user; used in conjunction with a public key in asymmetrical cryptography.
privileged entity controls
See privileged operations functions.
privileged mode
The mode designed to give the operating system access to the full range of instructions supported by the CPU.
privileged operations functions
Activities that require special access or privilege to perform within a secured IT environment. In most cases, these functions are restricted to administrators and system operators.
problem state
The state in which a process is actively executing.
procedure
In the context of security, a detailed step-by-step how-to document describing the exact actions necessary to implement a specific security mechanism, control, or solution.
process isolation
One of the fundamental security procedures put into place during system design. Basically, using process isolation mechanisms (whether part of the operating system or part of the hardware itself) ensures that each process has its own isolated memory space for storage of data and the actual executing application code itself.
processor
The central processing unit in a PC; it handles all functions on the system.
Program Evaluation Review Technique (PERT)
A project-scheduling tool. It is a method used to judge the size of a software product in development and calculate the standard deviation (SD) for risk assessment. PERT relates the estimated lowest possible size, the most likely size, and the highest possible size of each component. PERT is used to direct improvements to project management and software coding in order to produce more efficient software. As the capabilities of programming and management improve, the actual produced size of software should be smaller.
programmable read-only memory (PROM)
A PROM chip that does not have its contents “burned in” at the factory as is done with standard ROM chips. Instead, special functionality is installed that allows the end user to burn in the contents of the chip.
proprietary
A form of commercial business/private sector confidential information. If proprietary data is disclosed, it can have drastic effects on the competitive edge of an organization.
protection profile
From the Common Criteria for information technology security evaluation, the evaluation element in which a subject states its security needs.
protocol
A set of rules and restrictions that define how data is transmitted over a network medium (for example, twisted-pair cable, wireless transmission, and so on). Protocols make computer-to-computer communications possible.
proximity reader
A passive device, field-powered device, or transponder that detects the presence of authorized personnel and grants them physical entry into a facility. The proximity device is worn or held by the authorized bearer. When they pass a proximity reader, the reader is able to determine who the bearer is and whether they have authorized access.
proxy
A mechanism that copies packets from one network into another. The copy process also changes the source and destination address to protect the identity of the internal or private network.
prudent man rule
Invoked by the Federal Sentencing Guidelines, the rule that requires senior officials to perform their duties with the care that ordinary, prudent people would exercise under similar circumstances.
pseudo-flaws
A technique often used on honey pot systems and on critical resources to emulate well-known operating system vulnerabilities.
public
The lowest level of commercial business/private sector classification. Used for all data that does not fit in one of the higher classifications. This information is not readily disclosed, but if it is, it should not have a serious negative impact on the organization.
public key
A value that is used to encrypt or decrypt messages and is made public to any user and used with a private key in asymmetric cryptography.
public key infrastructure (PKI)
A hierarchy of trust relationships that makes it possible to facilitate communication between parties previously unknown to each other.
purging
The process of erasing of media so it can be reused in a less secure environment.
Q
qualitative decision making
A decision making process that takes nonnumerical factors, such as emotions, investor/customer confidence, workforce stability, and other concerns, into account. This type of data often results in categories of prioritization (such as high, medium, and low).
qualitative risk analysis
Scenario-oriented analysis using ranking and grading for exposure ratings and decisions.
quality assurance check
A form of personnel management and project management that oversees the development of a product. QA checks ensure that the product in development is consistent with stated standards, methods of practice, efficiency, and so on.
quantitative decision making
The use of numbers and formulas to reach a decision. Options are often expressed in terms of the dollar value to the business.
quantitative risk analysis
A method that assigns real dollar figures to the loss of an asset.
R
radiation monitoring
A specific form of sniffing or eavesdropping that involves the detection, capture, and recording of radio frequency signals and other radiated communication methods, including sound and light.
radio frequency identification (RFID)
A technology that uses electromagnetic or electrostatic coupling in the radio frequency (RF) portion of the electromagnetic spectrum to identify a specific device. Each RFID tag includes a unique identifier, so that when a nearby antenna/transceiver actives the tag, it transmits that identifier back to the antenna where that value is recorded, or used to trigger some kind of action. For example, most modern toll-road systems use RFID devices that drivers attach to the windshields of their cars, and each time a device is “read” by an antenna, the vehicle owner’s toll balance is incremented by the cost of that transit. RFID devices may also be used to track individuals (carrying tags), equipment (bearing tags), and so forth, within the premises of an enterprise for security monitoring.
radio frequency interference (RFI)
A type of noise that is generated by a wide number of common electrical appliances, including fluorescent lights, electrical cables, electric space heaters, computers, elevators, motors, electric magnets, and so on. RFI can affect many of the same systems EMI affects.
RADIUS
See Remote Authentication Dial-In User Service (RADIUS).
random access memory (RAM)
Readable and writable memory that contains information the computer uses during processing. RAM retains its contents only when power is continuously supplied to it.
random access storage
Devices, such as RAM and hard drives, that allow the operating system to request contents from any point within the media.
read-only memory (ROM)
Memory that can be read but cannot be written to.
ready state
The state in which a process is ready to execute but is waiting for its turn on the CPU.
real evidence
Items that can actually be brought into a court of law; also known as object evidence.
real memory
Typically the largest RAM storage resource available to a computer. It is normally composed of a number of dynamic RAM chips and therefore must be refreshed by the CPU on a periodic basis; also known as main memory or primary memory.
realized risk
The incident, occurrence, or event when a risk becomes a reality and a breach, attack, penetration, or intrusion has occurred that may or may not result in loss, damage, or disclosure of assets.
record
Contents of a table in a relational database.
record retention
The organizational policy that defines what information is maintained and for how long. In most cases, the records in question are audit trails of user activity. This may include file and resource access, logon patterns, email, and the use of privileges.
record sequence checking
Similar to hash total checking, but instead of verifying content integrity, it involves verifying packet or message sequence integrity.
recovery access control
A type of access control that is used to repair or restore resources, functions, and capabilities after a security policy violation.
recovery strategies
The practices, policies, and procedures to recover a business that include designating first responders to major incidents, performing critical follow-up tasks, and obtaining insurance to reduce risk of financial loss.
recovery time objective (RTO)
See maximum tolerable downtime (MTD).
reducing risk
The implementation of safeguards and countermeasures. Also referred to as mitigating risk.
reference monitor
A portion of the security kernel that validates user requests against the system’s access control mechanisms.
reference profile
The digitally stored sample of a biometric factor.
reference template
See reference profile.
referential integrity
Used to enforce relationships between two tables. One table in the relationship contains a foreign key that corresponds to the primary key of the other table in the relationship.
register
A limited amount of onboard memory in a CPU.
register address
The address of a register, which is a small memory location directly on the CPU. When the CPU needs information from one of those registers to complete an operation, it can simply use the register address (for example, “register one”) to access the information.
registration authority (RA)
A read-only version of a certificate authority that is able to distribute the CRL and perform certificate verification processes but is not able to create new certificates. An RA is used to share the workload of a CA.
regulatory policy
A policy that is required whenever industry or legal standards are applicable to your organization. This policy discusses the regulations that must be followed and outlines the procedures that should be used to elicit compliance.
reject risk
To deny that a risk exists or hope that by ignoring a risk, it will never be realized. It is an unacceptable response to risk. Also referred to as deny risk.
relational database
A database that consists of tables that contain a set of related records.
relationship
The association of information in tables of a relational database.
relevant
Characteristic of evidence that is applicable in determining a fact in a court of law.
Remote Authentication Dial-In User Service (RADIUS)
A service used to centralize the authentication of remote dial-up connections.
remote journaling
Transferring copies of the database transaction logs containing the transactions that occurred since the previous bulk transfer.
remote mirroring
Maintaining a live database server at the backup site. It is the most advanced database backup solution.
repeater
A network device used to amplify signals on network cabling to allow for longer distances between nodes. Can also be called a concentrator or amplifier.
replay attack
An attack in which a malicious user records the traffic between a client and server. The packets sent from the client to the server are then played back or retransmitted to the server with slight variations of the time stamp and source IP address (in other words, spoofing). In some cases, this allows the malicious user to restart an old communication link with a server. Also referred to as a playback attack.
residual risk
Risk that comprises specific threats to specific assets against which upper management chooses not to implement a safeguard. In other words, residual risk is the risk that management has chosen to accept rather than mitigate.
restricted interface model
A model that uses classification-based restrictions to offer only subject-specific authorized information and functions. One subject at one classification level will see one set of data and have access to one set of functions while another subject at a different classification level will see a different set of data and have access to a different set of functions.
retina scan
An example of a biometric factor, which is a behavioral or physiological characteristic that is unique to a subject. The blood vessel pattern at the back of the eyeball is used to establish identity or provide authentication.
Reverse Address Resolution Protocol (RARP)
A subprotocol of the TCP/IP protocol suite that operates at the Data Link layer (layer 2). RARP is used to discover the IP address of a system by polling using its MAC address.
reverse engineering
This is considered an unethical form of engineering. Programmers decompile code to understand all the intricate details of its functionality, especially when employed for the purpose of creating a similar, competing, or compatible product.
reverse hash matching
The process of discovering the original message that has been hashed by generating potential messages, hashing them, and comparing their hash value to the original. When H(M) = H(M’), then M = M’.
revocation
A mechanism that allows a PKI certificate to be canceled, effectively removing a user from the system.
RFC 1918
The public standard that defines public and private IP addresses.
Rijndael block cipher
A block cipher that was selected to replace DES. The Rijndael cipher allows the use of three key strengths: 128 bits, 192 bits, and 256 bits.
risk
The likelihood that any specific threat will exploit a specific vulnerability to cause harm to an asset. Risk is an assessment of probability, possibility, or chance. Risk = threat * vulnerability.
risk analysis
An element of risk management that includes analyzing an environment for risks, evaluating each risk as to its likelihood of occurring and cost of damage, assessing the cost of various countermeasures for each risk, and creating a cost/benefit report for safeguards to present to upper management.
risk management
A detailed process of identifying factors that could damage or disclose data, evaluating those factors in light of data value and countermeasure cost, and implementing cost-effective solutions for mitigating or reducing risk.
risk tolerance
The ability of an organization to absorb the losses associated with realized risks.
Rivest, Shamir, and Adleman (RSA)
A public key encryption algorithm named after Rivest, Shamir, and Adleman, its inventors.
role-based access control
A form of nondiscretionary access controls that employs job function roles to regulate subject access to objects.
root
The administrator level of a system.
rootkit
A specialized software package that allows hackers to gain expanded access to a system.
router
A network device used to control traffic flow on networks. Routers are often used to connect similar networks together and control traffic flow between them. They can function using statically defined routing tables or employ a dynamic routing system.
RSA
See Rivest, Shamir, and Adleman (RSA).
rule-based access control
A variation of mandatory access controls. A rule-based system uses a set of rules, restrictions, or filters to determine what can and cannot occur on the system, such as granting subject access, performing an action on an object, or accessing a resource. Firewalls, proxies, and routers are common examples of rule-based access control systems.
running key cipher
A form of cryptography in which the key is a designation of a changing source, such as the third page of the New York Times.
running state
The state in which a process is actively executing. This is another name for problem state.
S
S/MIME
See Secure Multipurpose Internet Mail Extensions (S/MIME).
sabotage
A criminal act committed against an organization by a knowledgeable employee.
safeguard
Anything that removes a vulnerability or protects against one or more specific threats. Also referred to as a countermeasure.
sag
Momentary low voltage.
salami attack
An attack performed by gathering small amounts of data to construct something of greater value or higher sensitivity.
salt
A random number appended to a password before hashing to increase randomness and ensure uniqueness in the resulting stored hash value.
sampling
A form of data reduction that allows an auditor to quickly determine the important issues or events from an audit trail.
sandbox
A security boundary within which a Java applet executes.
sanitization
Any number of processes that prepares media for destruction. Sanitization is the process that ensures that data cannot be recovered by any means from destroyed or discarded media. Sanitization can also be the actual means by which media is destroyed. Media can be sanitized by purging or degaussing without physically destroying the media.
scanning
Similar to “casing” a neighborhood prior to a burglary, the process by which a potential intruder looks for possible entryways into a system. Scanning can indicate that illegal activity will follow, so it is a good idea to treat scans as incidents and to collect evidence of scanning activity.
scavenging
A form of dumpster diving performed electronically. Online scavenging searches for useful information in the remnants of data left over after processes or tasks are completed. This could include audit trails, log files, memory dumps, variable settings, port mappings, cached data, and so on.
schema
The structure that holds the data that defines or describes a database. The schema is written using a Data Definition Language (DDL).
scripted access
A method to automate the logon process with a script that provides the logon credentials to a system. It is considered a form of single sign-on.
search warrant
A document obtained through the judicial system that allows law enforcement personnel to acquire evidence from a location without first alerting the individual believed to have perpetrated a crime.
secondary evidence
A copy of evidence or an oral description of the contents of best evidence.
secondary memory
Magnetic/optical media and other storage devices that contain data not immediately available to the CPU.
secondary storage
Data repositories that include magnetic and optical media, such as tapes, disks, hard drives, and CD/DVD storage.
second-tier attack
An assault that relies upon information or data gained from eavesdropping or other similar data-gathering techniques. In other words, it is an attack that is launched only after some other attack is completed.
Secret
A government/military classification, used for data of a secret nature. Unauthorized disclosure of secret data could cause serious damage to national security.
secure communication protocol
A protocol that uses encryption to provide security for the data transmitted by it.
Secure Electronic Transaction (SET)
A security protocol for the transmission of transactions over the Internet. SET is based on RSA encryption and DES. SET had the support of major credit card companies, such as Visa and MasterCard. However, it has mostly been abandoned in light of newer and more secure alternatives.
Secure Hash Algorithm (SHA)
A government standard hash function developed by the National Institute of Standards and Technology (NIST) and specified in an official government publication.
Secure HTTP (S-HTTP)
The second major protocol used to provide security on the World Wide Web.
Secure Multipurpose Internet Mail Extensions (S/MIME)
A protocol used to secure the transmission of email and attachments.
Secure Remote Procedure Call (S-RPC)
An authentication service. S-RPC is simply a means to prevent unauthorized execution of code on remote systems.
Secure Shell (SSH)
An end-to-end encryption technique. This suite of programs provides encrypted alternatives to common Internet applications such as FTP, Telnet, and rlogin. There are actually two versions of SSH. SSH1 supports the DES, 3DES, IDEA, and Blowfish algorithms. SSH2 drops support for DES and IDEA but adds support for several other algorithms.
Secure Sockets Layer (SSL)
An encryption protocol developed by Netscape to protect the communications between a web server and a web browser.
security association (SA)
In an IPSec session, the representation of the communication session and process of recording any configuration and status information about the connection.
security ID
A form of physical identification; generally contains a picture of the subject and/or a magnetic strip with additional information about a subject.
security kernel
The core set of operating system services that handles all user/application requests for access to system resources.
security label
An assigned classification or sensitivity level used in security models to determine the level of security required to protect an object and prevent unauthorized access.
security management planning
The act of thoroughly and systematically designing procedural and policy documentation to reduce risk and then to maintain risk at an acceptable level for a given environment.
security perimeter
The imaginary boundary that separates the trusted computing base from the rest of the system.
security policy
A document that defines the scope of security needs of an organization, prescribes solutions to manage security issues, and discusses the assets that need protection and the extent to which security solutions should go to provide the necessary protection.
security professional
Trained and experienced network, systems, and security engineer who is responsible for following the directives mandated by senior management.
security role
The part an individual plays in the overall scheme of security implementation and administration within an organization.
security target
The evaluation element from the Common Criteria for information technology security evaluation in which a vendor states the security features of its product.
senior management
A person or group who is ultimately responsible for the security maintained by an organization and who should be most concerned about the protection of its assets. They must sign off on all policy issues, and they will be held liable for overall success or failure of a security solution. It is the responsibility of senior management to show prudent due care. Also referred to as organizational owner and upper management.
sensitive
A commercial business/private sector classification used for data that is more sensitive than public data. A negative impact could occur for the company if sensitive data is disclosed.
sensitive but unclassified
A government/military classification used for data of a sensitive or private nature but significant damage would not occur if disclosed.
sensitivity
In regard to biometric devices, the level at which the device is configured for scanning.
separation of duties and responsibilities
A common practice to prevent any single subject from being able to circumvent or disable security mechanisms. By dividing core administration or high-authority responsibilities among several subjects, no one subject has sufficient access to perform significant malicious activities or bypass imposed security controls.
separation of privilege
The principle that builds upon the principle of least privilege. It requires the use of granular access permissions; that is, different permissions for each type of privileged operation. This allows designers to assign some processes rights to perform certain supervisory functions without granting them unrestricted access to the system.
Sequenced Packet Exchange (SPX)
The Transport layer protocol of the IPX/SPX protocol suite from Novell.
sequential storage
Devices that require that you read (or speed past) all of the data physically stored prior to the desired location. A common example of a sequential storage device is a magnetic tape drive.
Serial Line Internet Protocol (SLIP)
An older technology developed to support TCP/IP communications over asynchronous serial connections, such as serial cables or modem dial-up.
service bureaus
Businesses that lease computer time through contractual agreements and provide all IT needs in the event of some disaster or business interruption that requires a disaster recovery plan or business continuity plan to be enacted.
service-level agreement (SLA)
A contractual obligation to your clients that requires you to implement sound BCP practices. Also used to assure acceptable levels of service from suppliers for sound BCP practices.
SESAME
A ticket-based authentication mechanism similar to Kerberos.
session hijacking
An attack that occurs when a malicious individual intercepts part of a communication between an authorized user and a resource and then uses a hijacking technique to take over the session and assume the identity of the authorized user.
Session layer
Layer 5 of the OSI model.
shared key authentication (SKA)
A connection scheme for wireless networks that requires that some form of authentication must take place before network communications can occur. The 802.11 standard defines one optional technique for SKA known as WEP.
shielded twisted-pair (STP)
A twisted-pair wire that includes a metal foil wrapper inside the outer sheath to provide additional protection from EMI.
shoulder surfing
The act of gathering information from a system by observing the monitor or the use of the keyboard by the operator.
shrink-wrap license agreement
A license written on the outside of software packaging. Such licenses get their name because they commonly include a clause stating that you acknowledge agreement to the terms of the contract simply by breaking the shrink-wrap seal on the package.
signature-based detection
The process used by antivirus software to identify potential virus infections on a system.
signature dynamics
When used as a biometric, the use of the pattern and speed of a person writing their signature to establish identity or provide authentication.
Simple Integrity Axiom (SI Axiom)
An axiom of the Biba model that states that a subject at a specific classification level cannot read data with a lower classification level. This is often shortened to “no read down.”
Simple Key Management for IP (SKIP)
An encryption tool used to protect sessionless datagram protocols.
Simple Mail Transfer Protocol (SMTP)
The primary protocol used to move email messages from clients to servers and from server to server.
Simple Security Property (SS property)
A property of the Bell-LaPadula model that states that a subject at a specific classification level cannot read data with a higher classification level. This is often shortened to “no read up.”
simulation tests
A test in which disaster recovery team members are presented with a scenario and asked to develop an appropriate response. Some of these response measures are then tested. This may involve the interruption of noncritical business activities and the use of some operational personnel.
single loss expectancy (SLE)
The cost associated with a single realized risk against a specific asset. The SLE indicates the exact amount of loss an organization would experience if an asset were harmed by a specific threat. SLE = asset value ($) * exposure factor (EF).
single sign-on (SSO)
A mechanism that allows subjects to authenticate themselves only once to a system. With SSO, once subjects are authenticated, they can freely roam the network and access resources and service without being rechallenged for authentication.
single state
Systems that require the use of policy mechanisms to manage information at different levels. In this type of arrangement, security administrators approve a processor and system to handle only one security level at a time.
single-use passwords
A variant of dynamic passwords that are changed every time they are used.
Skipjack
Associated with the Escrowed Encryption Standard, an algorithm that operates on 64-bit blocks of text. It uses an 80-bit key and supports the same four modes of operation supported by DES. Skipjack was proposed but never implemented by the U.S. government. It provides the cryptographic routines supporting the Clipper and Capstone high-speed encryption chips designed for mainstream commercial use.
smart card
Credit-card-sized ID, badge, or security pass that has a magnetic strip, bar code, or integrated circuit chip embedded in it. Smart cards can contain information about the authorized bearer that can be used for identification and/or authentication purposes.
smurf attack
A type of DoS. A smurf attack occurs when an amplifying server or network is used to flood a victim with useless data.
sniffer attack
Any activity that results in a malicious user obtaining information about a network or the traffic over that network. A sniffer is often a packet-capturing program that duplicates the contents of packets traveling over the network medium into a file. Also referred to as a snooping attack.
sniffing
A form of network traffic monitoring. Sniffing often involves the capture or duplication of network traffic for examination, re-creation, and extraction.
snooping attack
See sniffer attack.
social engineering
A skill by which an unauthorized person gains the trust of someone inside your organization and encourages them to make a change to the IT system in order to grant them access.
socket
Another name for a port.
software IP encryption (SWIPE)
A layer 3 security protocol for IP. It provides authentication, integrity, and confidentiality using an encapsulation protocol.
spam
The term describing unwanted email, newsgroup, or discussion forum messages. Spam can be as innocuous as an advertisement from a well-meaning vendor or as malignant as floods of unrequested messages with viruses or Trojan horses attached.
spamming attacks
Sending significant amounts of spam to a system in order to cause a DoS or general irritation, consume storage space, or consume bandwidth and processing capabilities.
spike
Momentary high voltage.
split knowledge
The specific application of the ideas of separation of duties and two-man control into a single solution. The basic idea is that the information or privilege required to perform an operation is divided among multiple users. This ensures that no single person has sufficient privileges to compromise the security of the environment.
spoofing
The act of replacing the valid source and/or destination IP address and node numbers with false ones.
spoofing attack
Any attack that involves spoofed or modified packets.
standards
Documents that define compulsory requirements for the homogenous use of hardware, software, technology, and security controls. They provide a course of action by which technology and procedures are uniformly implemented throughout an organization. Standards are tactical documents that define steps or methods to accomplish the goals and overall direction defined by security policies.
state
A snapshot of a system at a specific instance in time.
state machine model
A system that is designed so that no matter what function is performed, it is always a secure system.
stateful inspection firewall
A firewall that evaluates the state or the context of network traffic. By examining source and destination address, application usage, source of origin, and relationship between current packets with the previous packets of the same session, stateful inspection firewalls are able to grant a broader range of access for authorized users and activities and actively watch for and block unauthorized users and activities. Stateful inspection firewalls are known as third-generation firewalls.
static packet-filtering firewall
A firewall that filters traffic by examining data from a message header. Usually the rules are concerned with source, destination, and port addresses. Static packet-filtering firewalls as known as first-generation firewalls.
static password
Password that does not change over time or that remains the same for a significant period of time.
static token
A physical means to provide identity, usually not employed as an authentication factor. Examples include a swipe card, a smart card, a floppy disk, a USB RAM dongle, or even something as simple as a key to operate a physical lock.
station set identifier (SSID)
The name of a wireless network that each wireless client must know in order to communicate with the host access point.
statistical attack
This type of attack exploits statistical weaknesses in a cryptosystem, such as such as floating-point errors or an inability to produce random numbers. It attempts to find vulnerabilities in the hardware or operating system hosting the cryptography application.
statistical intrusion detection
See behavior-based detection.
stealth virus
A virus that hides itself by actually tampering with the operating system to fool antivirus packages into thinking that everything is functioning normally.
steganography
The act of embedding messages within another message, commonly used within an image or a WAV file.
stop error
The security response of an operating system, such as Windows, when an application performs an illegal operation, such as accessing hardware or modifying/accessing the memory space of another process.
stopped state
The state in which a process is finished or must be terminated. At this point, the operating system can recover all memory and other resources allocated to the process and reuse them for other processes as needed.
strategic plan
A long-term plan that is fairly stable. It defines the organization’s goals, mission, and objectives. A strategic plan is useful for about five years if it is maintained and updated annually. The strategic plan also serves as the planning horizon.
stream attack
A type of DoS. A stream attack occurs when a large number of packets are sent to numerous ports on the victim system using random source and sequence numbers. The processing performed by the victim system attempting to make sense of the data will result in a DoS. Also referred to as flooding.
stream ciphers
Ciphers that operate on each character or bit of a message (or data stream) one character/bit at a time.
strong password
Password that is resistant to dictionary and brute-force attacks.
Structured Query Language (SQL)
The standard language used by relational databases to enter and extract the information stored in them.
structured walk-through
A type of disaster recovery test, often referred to as a “table-top exercise,” in which members of the disaster recovery team gather in a large conference room and role-play a disaster scenario.
subject
An active entity that seeks information about or data from passive objects through the exercise of access. A subject can be a user, a program, a process, a file, a computer, a database, and so on.
subpoena
A court order that compels an individual or organization to surrender evidence or to appear in court.
substitution cipher
Cipher that uses an encryption algorithm to replace each character or bit of the plain-text message with a different character, such as a Caesar cipher.
supervisor state (or supervisory state)
The state in which a process is operating in a privileged, all-access mode.
supervisory mode
Mode in which processes at layer 0 run, which is the ring where the operating system itself resides.
surge
Prolonged high voltage.
SWIPE
See software IP encryption (SWIPE).
switch
A network device that is an intelligent hub because it knows the addresses of the systems connected on each outbound port. Instead of repeating traffic on every outbound port, a switch repeats only traffic out of the port on which the destination is known to exist. Switches offer greater efficiency for traffic delivery, create separate broadcast and collision domains, and improve the overall throughput of data.
Switched Multimegabit Data Services (SMDS)
A connectionless network communication service. SMDS provides bandwidth on demand. SMDS is a preferred connection mechanism for linking remote LANs that communicate infrequently.
switched virtual circuit (SVC)
A virtual circuit that must be rebuilt each time it is used; similar to a dial-up connection.
semantic integrity mechanisms
A common security feature of a DBMS. This feature ensures that no structural or semantic rules are violated. It also checks that all stored data types are within valid domain ranges, that only logical values exist, and that any and all uniqueness constraints are met.
symmetric key
An algorithm that relies upon a “shared secret” encryption key that is distributed to all members who participate in communications. This key is used by all parties to both encrypt and decrypt messages.
symmetric multiprocessing (SMP)
A type of system in which the processors share not only a common operating system but also a common data bus and memory resources. In this type of arrangement, it is not normally possible to use more than 16 processors.
SYN flood attack
A type of DoS. A SYN flood attack is waged by not sending the final ACK packet, which breaks the standard three-way handshake used by TCP/IP to initiate communication sessions.
Synchronous Data Link Control (SDLC)
A layer 2 protocol employed by networks with dedicated or leased lines. SDLC was developed by IBM for remote communications with SNA systems. SDLC is a bit-oriented synchronous protocol.
synchronous dynamic password token
Tokens used in a token device that generates passwords at fixed time intervals. Time interval tokens require that the clock of the authentication server and the token device be synchronized. The generated password is entered by the subject along with a PIN, passphrase, or password.
system call
A process by which an object in a less-trusted protection ring requests access to resources or functionality by objects in more-trusted protection rings.
system high mode
See system-high security mode.
system-high security mode
Mode in which systems are authorized to process only information that all system users are cleared to read and have a valid need to know. Systems running in this mode are not trusted to maintain separation between security levels, and all information processed by these systems must be handled as if it were classified at the same level as the most highly classified information processed by the system.
T
table
The main building block of a relational database; also known as a relation.
TACACS
See Terminal Access Controller Access Control System (TACACS).
tactical plan
A midterm plan developed to provide more details on accomplishing the goals set forth in the strategic plan. A tactical plan is typically useful for about a year. It often prescribes and schedules the tasks necessary to accomplish organizational goals.
Take-Grant model
A model that employs a directed graph to dictate how rights can be passed from one subject to another or from a subject to an object. Simply put, a subject with the grant right can grant another subject or another object any other right they possess. Likewise, a subject with the take right can take a right from another subject.
task-based
An access control methodology in which access is granted based on work tasks or operations.
TCP wrapper
An application that can serve as a basic firewall by restricting access based on user IDs or systems IDs.
teardrop attack
A type of DoS. A teardrop attack occurs when an attacker exploits a bug in operating systems. The bug exists in the routines used to reassemble fragmented packets. An attacker sends numerous specially formatted fragmented packets to the victim, which causes the system to freeze or crash.
technical access control
The hardware or software mechanisms used to manage access to resources and systems and provide protection for those resources and systems. Examples of logical or technical access controls include encryption, smart cards, passwords, biometrics, constrained interfaces, access control lists, protocols, firewalls, routers, IDEs, and clipping levels. The same as logical access control.
technical physical security controls
Security controls that use technology to implement some form of physical security, including intrusion detection systems, alarms, CCTV, monitoring, HVAC, power supplies, and fire detection and suppression.
TEMPEST
The study and control of electronic signals produced by various types of electronic hardware, such as computers, televisions, phones, and so on. Its primary goal is to prevent EM and RF radiation from leaving a strictly defined area so as to eliminate the possibility of external radiation monitoring, eavesdropping, and signal sniffing.
Terminal Access Controller Access Control System (TACACS)
An alternative to RADIUS. TACACS is available in three versions: original TACACS, XTACACS (extended TACACS), and TACACS+. TACACS integrates the authentication and authorization processes. XTACACS keeps the authentication, authorization, and accounting processes separate. TACACS+ improves XTACACS by adding two-factor authentication.
terrorist attacks
Attacks that differ from military and intelligence attacks in that the purpose is to disrupt normal life, whereas a military or intelligence attack is designed to extract secret information.
test data method
A form of program testing that examines the extent of the system testing to locate untested program logic.
testimonial evidence
Evidence that consists of the testimony of a witness, either verbal testimony in court or written testimony in a recorded deposition.
thicknet
See 10Base5.
thin client
A term used to describe a workstation that has little or no local processing or storage capacity. A thin client is used to connect to and operate a remote system.
thinnet
See 10Base2.
threat
A potential occurrence that may cause an undesirable or unwanted outcome for an organization or a specific asset.
threat agents
People, programs, hardware, or systems that intentionally exploit vulnerabilities.
threat events
Accidental exploitations of vulnerabilities.
thrill attacks
An attack launched by crackers with few true skills. The main motivation behind thrill attacks is the “high” of getting into a system.
throughput rate
The rate at which a biometric device can scan and authenticate subjects. A rate of about six seconds or faster is required for general acceptance of a specific biometric control.
ticket
An electronic authentication factor used by the Kerberos authentication system.
ticket-granting service (TGS)
An element of the Kerberos authentication system. The TGS manages the assignment and expiration of tickets. Tickets are used by subjects to gain access to objects.
time-of-check (TOC)
The time at which a subject checks on the status of an object.
time-of-check-to-time-of-use (TOCTTOU)
A timing vulnerability that occurs when a program checks access permissions too far in advance of a resource request.
time-of-use (TOU)
The time at which the decision is made by a subject to access an object.
time slice
A single chunk or division of processing time.
token
See token device.
token device
A password-generating device that subjects must carry with them. Token devices are a form of a “something you have” (Type 2) authentication factor.
token ring
A token-passing LAN technology.
Top Secret
The highest level of government/military classification. Unauthorized disclosure of top-secret data will cause exceptionally grave damage to national security.
topology
The physical layout of network devices and connective cabling. The common network topologies are ring, bus, star, and mesh.
total risk
The amount of risk an organization would face if no safeguards were implemented. Threats * vulnerabilities * asset value = total risk.
trade secret
Intellectual property that is absolutely critical to a business and would cause significant damage if it were disclosed to competitors and/or the public.
trademark
A registered word, slogan, or logos used to identify a company and its products or services.
traffic analysis
A form of monitoring in which the flow of packets rather than the actual content of packets is examined. Also referred to as trend analysis.
training
The task of teaching employees to perform their work tasks and to comply with the security policy. All new employees require some level of training so they will be able to properly comply with all standards, guidelines, and procedures mandated by the security policy.
transferring risk
Placing the cost of loss from a realized risk onto another entity or organization, such as purchasing insurance. Also referred to as assigning risk.
transient
A short duration of line noise disturbance.
Transmission Control Protocol (TCP)
A connection-oriented protocol located at layer 4 of the OSI model.
transmission error correction
A capability built into connection- or session-oriented protocols and services. If it is determined that a message, in whole or in part, was corrupted, altered, or lost, a request can be made for the source to resend all or part of the message.
transmission logging
A form of auditing focused on communications. Transmission logging records the details about source, destination, time stamps, identification codes, transmission status, number of packets, size of message, and so on.
transparency
A characteristic of a service, security control, or access mechanism that is unseen by users. Transparency is often a desirable feature for security controls.
Transport layer
Layer 4 of the OSI model.
transport mode
A mode of IPSec when used in a VPN. In transport mode, the IP packet data is encrypted, but the header of the packet is not.
transposition cipher
Cipher that uses an encryption algorithm to rearrange the letters of a plain-text message to form the cipher-text message.
trap door
Undocumented command sequence that allows software developers to bypass normal access restrictions.
traverse mode noise
EMI noise generated by the difference in power between the hot and neutral wires of a power source or operating electrical equipment.
trend analysis
See traffic analysis.
Triple DES (3DES)
A standard that uses three iterations of DES with two or three different keys to increase the effective key strength to 112 bits.
Trojan horse
A malicious code object that appears to be a benevolent program—such as a game or simple utility that performs the “cover” functions as advertised but also carries an unknown payload, such as a virus.
trust
A security bridge established to share resources from one domain to another. A trust is established between two domains to allow users from one domain to access resources in another. Trusts can be one-way only, or they can be two-way.
trusted computing base (TCB)
The combination of hardware, software, and controls that form a trusted base that enforces your security policy.
trusted path
Secure channel used by the TCB to communicate with the rest of the system.
trusted recovery process
On a secured system, a process that ensures the system always returns to a secure state after an error, failure, or reboot.
trusted system
A secured computer system.
tunnel mode
A mode of IPSec when used in a VPN. In tunnel mode, the entire IP packet is encrypted and a new header is added to the packet to govern transmission through the tunnel.
tunneling
A network communications process that protects the contents of protocol packets by encapsulating them in packets of another protocol.
turnstile
A form of gate that prevents more than one person at a time from gaining entry and often restricts movement in one direction.
twisted-pair
See 10Base-T.
two-factor authentication
Authentication that requires two factors.
Type 1 authentication factor
Something you know, such as a password, personal identification number (PIN), combination lock, passphrase, mother’s maiden name, or favorite color.
Type 2 authentication factor
Something you have, such as a smart card, ATM card, token device, or memory card.
Type 3 authentication factor
Something you are, such as fingerprints, voice print, retina pattern, iris pattern, face shape, palm topology, or hand geometry.
Type 1 error
See false rejection rate (FRR).
Type 2 error
See false acceptance rate (FAR).
U
unclassified
The lowest level of government/military classification. Used for data that is neither sensitive nor classified. Disclosure of unclassified data does not compromise confidentiality, and it doesn’t cause any noticeable damage.
unicast
A communications transmission to a single identified recipient.
Uniform Computer Information Transactions Act (UCITA)
A federal law designed for adoption by each of the 50 states to provide a common framework for the conduct of computer-related business transactions.
uninterruptible power supply (UPS)
A type of self-charging battery that can be used to supply consistent clean power to sensitive equipment. A UPS functions basically by taking power in from the wall outlet, storing it in a battery, pulling power out of the battery, and then feeding that power to whatever devices are connected to it. By directing current through its battery, it is able to maintain a consistent clean power supply.
unit testing
A method of testing software. Each unit of code is tested independently to discover any errors or omissions and to ensure that it functions properly. Unit testing should be performed by the development staff.
unshielded twisted-pair (UTP)
A twisted-pair wire that does not include additional EMI protection. Most twisted-pair wiring is UTP.
upper management
See senior management.
USA Patriot Act of 2001
An act implemented after the September 11, 2001, terrorist attacks. It greatly broadened the powers of law enforcement organizations and intelligence agencies across a number of areas, including the monitoring of electronic communications.
user
Any person who has access to the secured system. A user’s access is tied to their work tasks and is limited so they have only enough access to perform the tasks necessary for their job position (in other words, principle of least privilege). Also referred to as an end user and employee.
User Datagram Protocol (UDP)
A connectionless protocol located at layer 4 of the OSI model.
user mode
The basic mode used by the CPU when executing user applications.
V
VENONA
One of the major intelligence successes of the United States resulted when cryptanalysts broke a top-secret Soviet cryptosystem, i.e., VENONA, that relied upon the use of one-time pads
Vernam cipher
A device that implements a 26-character modulo 26 substitution cipher. It functions as a one-time pad.
view
A client interface used to interact with a database. The view limits what clients can see and what functions they can perform.
Vigenere cipher
A polyalphabetic substitution cipher.
violation analysis
A form of auditing that uses clipping levels.
virtual machine
A software simulation of a computer within which a process executes. Each virtual machine has its own memory address space and communication between virtual machines is securely controlled.
virtual memory
A special type of secondary memory that is managed by the operating system in such a manner that it appears to be real memory.
virtual private network (VPN)
A network connection established between two systems over an existing private or public network. A VPN provides confidentiality and integrity for network traffic through the use of encryption.
virtual private network (VPN) protocol
The protocols, such as PPTP, L2TP, and IPSec, that are used to create VPNs.
virus
The oldest form of malicious code objects that plague cyberspace. Once they are in a system, they attach themselves to legitimate operating system and user files and applications and normally perform some sort of undesirable action, ranging from the somewhat innocuous display of an annoying message on the screen to the more malicious destruction of the entire local file system.
Voice over IP (VoIP)
A network service that provides voice communication services by transporting the voice traffic as network packets over an IP network.
voice pattern
An example of a biometric factor, which is a behavioral or physiological characteristic that is unique to a subject. The speech, tone, modulation, and pitch patterns of a person’s voice are used to establish identity or provide authentication.
volatile
See volatile storage.
volatile storage
A storage medium, such as RAM, that loses its contents when power is removed from the resource.
voluntarily surrender
The act of willingly handing over evidence.
vulnerability
The absence or weakness of a safeguard or countermeasure. In other words, a vulnerability is the existence of a flaw, loophole, oversight, error, limitation, frailty, or susceptibility in the IT infrastructure or any other aspect of an organization.
vulnerability scan
A test performed on a system to find weaknesses in the security infrastructure.
vulnerability scanner
A tool used to test a system for known security vulnerabilities and weaknesses. Vulnerability scanners are used to generate reports that indicate the areas or aspects of the system that need to be managed to improve security.
W
wait state
The state in which a process is ready to execute but is waiting for an operation such as keyboard input, printing, or file writing to complete.
war dialing
The act of using a modem to search for a system that will accept inbound connection attempts.
warm site
A middle ground between hot sites and cold sites for disaster recovery specialists. A warm site always contains the equipment and data circuits necessary to rapidly establish operations but does not typically contain copies of the client’s data.
warning banners
Messages used to inform would-be intruders or attempted security policy violators that their intended activities are restricted and that any further activities will be audited and monitored. A warning banner is basically an electronic equivalent of a no trespassing sign.
well-known ports
The first 1,024 ports of TCP and UDP. They are usually assigned to commonly used services and applications.
wet pipe system
A fire suppression system that is always full of water. Water discharges immediately when triggered by a fire or smoke. Also known as a closed head system.
white box testing
A form of program testing that examines the internal logical structures of a program.
wide area network (WAN)
A network or a network of LANs that is geographically diverse. Often dedicated leased lines are used to establish connections between distant components.
WiFi Protected Access (WPA)
An early alternative to WEP based on a secret passphrase and employing the LEAP and TKIP crypto systems. It is attackable through passphrase guessing.
WiMax (802.16)
A wireless standard that defines citywide wireless access technologies. This standard has yet to be widely deployed.
WinNuke attack
A type of DoS. A WinNuke attack is a specialized assault against Windows 95 systems. Out-of-band TCP data is sent to a victim’s system, which causes the OS to freeze.
Wired Equivalent Privacy (WEP)
A form of encrypted authentication that employs RC4. WEP supports only one-way authentication from client to WAP. WEP is considered insufficient for security because of several deficiencies in its design and implementation.
Wireless Application Protocol (WAP)
A functioning industry-driven protocol stack that allows users through their WAP-capable devices, such as cell phones, to communicate over a carrier’s network with the Internet.
wireless networking (802.11)
A form of networking that uses radio waves as the connection medium following the 802.11 standard. Often called WiFi.
work function or work factor
A way of measuring the strength of a cryptography system by measuring the effort in terms of cost and/or time. Usually the time and effort required to perform a complete brute-force attack against an encryption system is what the work function rating represents. The security and protection offered by a cryptosystem is directly proportional to the value of the work function/factor.
worm
A form of malicious code that is self-replicating but is not designed to impose direct harm on host systems. The primary purpose of a worm is to replicate itself to other systems and gather information. Worms are usually very prolific and often cause a denial of service because of their consumption of system resources and network bandwidth in their attempt to self-replicate.
X
X.25
An older WAN protocol that uses carrier switching to provide end-to-end connections over a shared network medium.
XOR
A function that returns a true value when only one of the input values is true. If both values are false or both values are true, the output of the XOR function is false.
Z
zero knowledge proof
A concept of communication whereby a specific type of information is exchanged but no real data is exchanged. Great examples of this idea are digital signatures and digital certificates.
Zero Knowledge Teams
These possess only primary information about an organization during a security assessment or penetration test.