8. Adding Signatures and Security
Lesson overview
In this lesson, you’ll do the following:
• Use Acrobat Reader in Protected Mode (Windows only).
• Apply password protection to a file to restrict who can open it.
• Apply a password to prevent others from printing or changing a PDF file.
• Use Adobe Sign to send documents for digital signatures.
• Create a digital ID that includes an image.
• Sign documents using a digital ID.
• Certify a document.
This lesson will take approximately 45 minutes to complete. Copy the Lesson08 folder onto your hard drive if you haven’t already done so.
You can keep your PDF documents secure through password protection, certification, and digital signatures.
Getting started
Acrobat DC provides several tools to help you secure your PDF documents. You can use passwords to prevent unauthorized users from opening, printing, or editing PDF files. You can use a certificate to encrypt PDF documents so that only an approved list of users can open them. With an Acrobat or Creative Cloud subscription, you can use Adobe Sign to send a document to others for their digital signatures. Alternatively, you can use digital IDs to sign documents and certify PDF documents. If you want to save security settings for later use, you can create a security policy that stores security settings. In Acrobat Pro, you can also permanently remove sensitive content from your PDF documents using the Redaction feature (see Lesson 5, “Editing Content in PDF Files”).
First you’ll learn about Protected Mode in Acrobat Reader for Windows, and then you’ll work with the security features in Acrobat itself.
Viewing documents in Protected Mode in Reader (Windows only)
As mentioned in Lesson 1, by default, Acrobat Reader DC for Windows opens PDF files in Protected Mode (known as “sandboxing” to IT professionals). In Protected Mode, Reader confines any processes to the application itself, so that potentially malicious PDF files do not have access to your computer and its system files.
To complete this exercise, you must use Acrobat Reader DC for Windows, but Acrobat Reader is not automatically installed with Acrobat. You can download the free installer at get.adobe.com/reader.
1 Open Acrobat Reader DC in Windows.
2 Choose File > Open, and navigate to the Lesson08/Assets folder.
3 Select Travel Guide.pdf, and click Open.
The Travel Guide.pdf file opens in Acrobat Reader. You can access all of the Reader menus and tools. However, the PDF file cannot make calls to your system outside the Reader environment.
4 Choose File > Properties.
5 In the Document Properties dialog box, click the Advanced tab.
6 View the Protected Mode status at the bottom of the dialog box. It’s On by default.
You can always confirm that a document is open in Protected Mode by viewing the Document Properties dialog box.
7 Click OK to close the Document Properties dialog box. Then close the Travel Guide.pdf file, and quit Reader.
Adobe strongly recommends that you use Acrobat Reader in Protected Mode. However, some third-party plug-ins may not work in Protected Mode. If you need to disable Protected Mode, choose Edit > Preferences, select Security (Enhanced) from the list of categories, and deselect Enable Protected Mode At Startup. You’ll need to restart Acrobat Reader for the changes to take effect.
• Add passwords and set security options to restrict opening, editing, and printing PDFs.
• Encrypt a document so that only a specified set of users has access to it.
• Save the PDF as a certified document. Certifying a PDF adds a certifying signature (which may be visible or invisible) that lets the document author restrict changes to the document.
• Apply server-based security policies to PDFs (for example, using Adobe LiveCycle Rights Management). Server-based security policies are especially useful if you want others to have access to PDFs for a limited time.
Viewing security settings
When you open a document that has restricted access or some type of security applied to it, you’ll see a Security Settings button (
) in the navigation pane to the left of the document window.
1 Start Acrobat. Then choose File > Open, navigate to the Lesson08/Assets folder, and open the Sponsor_secure.pdf file. If the Acrobat Security Settings dialog box appears, click Cancel; if the Trusted Certificates Update dialog box appears, click OK.
2 Notice that “(SECURED)” appears after the filename in the title bar.
3 Open the Comment tool, and notice that the commenting and text markup tools are unavailable.
4 Click the triangle on the left side of the document window to open the navigation pane, if it isn’t already open. Click the Security Settings button () in the navigation pane to view the security settings. Click the Permission Details link to view more detail.
The Document Properties dialog box lists each action and whether it is allowed. As you read down the list, you’ll see that commenting is not allowed, which is why the related tools are dimmed. Signing, printing, editing, and other actions are also not allowed in this document.
5 When you have finished reviewing the information, click OK to close the Document Properties dialog box.
6 Choose File > Close to close the Sponsor_secure.pdf file.
Adding security to PDF files
You can add security to your Adobe PDF files when you first create them, or you can add it later. You can even add security to files that you receive from someone else, unless the creator of the document has limited who can change security settings.
Now, you’ll add password protection to limit who can open your document and who can change the security settings.
Adding passwords
You can add two kinds of passwords to protect your Adobe PDF documents. A Document Open password allows only users who enter the password to open the document. A Permissions password allows only users who enter the password to change the permissions for the document, so that they can print or modify the document or perform other changes you’ve restricted.
Tip
As long as you have the password, you can open password-protected and encrypted PDF files on tablets and phones using the Acrobat DC mobile app. To learn more, see “Going mobile” on page 6.
You’ll add protection to a logo file so that no one can change its contents and so that unauthorized users can’t open and use the file.
1 Choose File > Open, navigate to the Lesson08/Assets folder, and open the Local_Logo.pdf file.
There is no Security Settings button in the navigation pane, because no security has been applied to this document.
2 Choose File > Save As, save the file in the Lesson08 folder, and name the file Local_Logo1.pdf.
3 Click Protect in the Tools pane.
4 In the Protect toolbar, click Encrypt, and choose 2 Encrypt With Password. Click Yes when Acrobat asks whether you want to add security to the document.
The Password Security – Settings dialog box opens automatically.
5 Select the Require A Password To Open The Document option, and then type Logo1234;^bg for the password.
Acrobat rates the password’s strength. Stronger passwords include both uppercase and lowercase letters, numbers, punctuation marks, and symbols. Longer passwords also tend to be harder to guess. If it’s critical that a document remain confidential, use a strong password. You’ll share this password with anyone who you want to allow to open the document. Remember that passwords are case-sensitive.
Tip
Always record your passwords in a secure location. If you forget your password, you can’t recover it from the document. You might also want to store an unprotected copy of the document in a secure location.
Now you’ll add a second password that controls who is allowed to change printing, editing, and security settings for the file.
6 Under Permissions, select Restrict Editing And Printing Of The Document.
7 From the Printing Allowed menu, choose Low Resolution (150 dpi). You can prohibit printing, allow only low-resolution printing, or allow high-resolution printing.
8 From the Changes Allowed menu, choose Commenting, Filling In Form Fields, And Signing Existing Signature Fields to allow users to comment on the logo. You can prohibit all changes, some changes, or only prohibit viewers from extracting pages.
9 In the Change Permissions Password box, type Logo5678;^bg. Your open password and permissions password can’t be the same.
Next, you’ll set the compatibility level. The default compatibility level is compatibility with Acrobat 7.0 or later. If you’re sure that all your viewers have Acrobat X or later, you should choose Acrobat X And Later, as it provides the strongest protection. If you think that some of your viewers may still be using Acrobat 6.0, select Acrobat 6.0 And Later. Be aware, however, that this setting may use a lower encryption level.
10 Make sure Acrobat 7.0 And Later is selected in the Compatibility menu.
11 Click OK to apply your changes.
12 In the Confirm Document Open Password dialog box, re-enter the Open Password, Logo1234;^bg. Then click OK.
13 Read the alert that warns you that some third-party applications may not honor the security settings in the PDF file, and click OK to clear the alert.
14 In the Confirm Permissions Password dialog box, re-enter the Permissions Password, Logo5678;^bg. Then click OK, and click OK again to clear the alert.
The security changes don’t take effect until you save the file.
15 Choose File > Save to save the security changes.
16 Click the Security Settings button () in the navigation pane, and then click the Permission Details link. The limitations you set are in effect.
17 Click OK to close the Document Properties dialog box, and then choose File > Close to close the Local_Logo1.pdf file.
Opening password-protected files
Now you’ll check the security that you’ve added to your file.
1 Choose File > Open, and open the Local_Logo1.pdf file in the Lesson08 folder.
Acrobat prompts you to enter the required password to open the file.
2 Enter the password (Logo1234;^bg), and click OK.
Notice that “(SECURED)” has been appended to the filename at the top of the application window.
Now you’ll test the permissions password.
3 Click the Security Settings button () in the navigation pane, and click the Permission Details link.
4 In the Document Properties dialog box, try changing the Security Method from Password Security to No Security.
Acrobat prompts you to enter the Permissions password.
5 Enter the password (Logo5678;^bg), and click OK; then click OK again to confirm that you want to remove security.
All restrictions are now removed from the file.
6 Click OK to close the Document Properties dialog box.
7 Choose File > Close, and close the file without saving the changes. Because you aren’t saving your changes, the passwords remain in effect next time you open the file.
About digital signatures
Signing a document electronically offers several advantages, not least of which is that you can email the signed document rather than having to fax it or send it by courier. Although digitally signing a document doesn’t necessarily prevent people from changing the document, it does allow you to track any changes made after the signature is added and revert to the signed version if necessary. (You can prevent users from changing your document by applying appropriate security to the document.)
With an Acrobat subscription or a Creative Cloud subscription, you can use Adobe Sign (formerly EchoSign) to sign a document or send it out for signatures. Adobe Sign makes the process of signing documents electronically fast and simple.
You can also sign a document using certificates: You must obtain a digital ID from a third-party provider or create a digital ID (self-signed digital ID) for yourself in Acrobat. The digital ID contains a private key that is used to add the digital signature and a certificate that you share with those who need to validate your signature.
For information about Adobe security partners that offer third-party digital IDs and other security solutions, visit the Adobe website at www.adobe.com.
Sending a document for others to sign
The easiest way to invite someone else to sign a document electronically is to use Adobe Sign. You’ll prepare a document for Adobe Sign, and then send it out for signatures. If you’re working with others, you’ll send it to a colleague to sign. However, if you’re working alone, you’ll need to have an alternate email address to use; you can create free email addresses through services such as Gmail or Yahoo Mail.
Preparing the form
If you send a document without preparing it, Adobe Sign affixes signature and email fields to the bottom of the document. That may be all you need if, for example, you require only confirmation that someone has read a document. However, most forms require signatures or initials in specific locations, and many require other information as well. You’ll prepare a form with standard signature blocks for the client (GlobalCorp) and the vendor (Custom Solutions).
1 In Acrobat, choose File > Open, navigate to the Lesson08/Assets folder, and double-click Statement of Work.pdf.
Tip
You can combine multiple documents into a single file for signatures: Open the Send For Signature tool, add the documents to the file list, and then click Prepare Form. Acrobat will prompt you to combine the documents.
This document is a contract for services. The signature blocks are on the last page.
2 Click Send For Signature in the Tools pane.
The Send For Signature tool opens.
3 Confirm that Statement of Work.pdf is the selected file.
Your document doesn’t include any form fields that Adobe Sign will recognize, so you’ll need to prepare it before sending it.
4 Click Prepare Form.
Acrobat opens the Prepare Form tool, and it analyzes the document for existing and likely form fields.
5 Click OK when Acrobat reports that no form fields were found.
6 Go to page 4 in the document to see the signature lines.
7 Select the Digital Signature Field tool (
) in the Prepare Form toolbar.
8 Drag a signature form field above the GlobalCorp signature line.
9 Make sure Signer is chosen in the Who Needs To Sign This Field? menu.
When Sender or one of the Signer options is chosen, the form field becomes an Adobe Sign field. If Anyone is chosen in the Who Needs To Sign This Field? menu, Adobe Sign won’t recognize the field. You can add the signer’s email address, too.
10 Select the Name Field tool (
) in the Prepare Form toolbar, drag a field above the GlobalCorp Name line, and make sure Signer is chosen in the Who Needs to Sign This Field? menu.
11 Select the Title Field tool (
) in the Prepare Form toolbar, drag a form field above the GlobalCorp Title line, and make sure Signer is chosen.
When the recipient signs the signature line, Adobe Sign will automatically populate the Name field with the signer’s name. It will also automatically add the current date to the Date field.
12 Select the Date Field tool (
) in the Prepare Form toolbar, drag a form field above the GlobalCorp Date line, and make sure Signer is chosen.
You’ve created the fields for the GlobalCorp signer. Now you’ll create the fields for the Custom Solutions representative. Because Custom Solutions is sending the document out, you’ll choose Sender from the Who Needs To Sign This Field? menu.
13 Select the Digital Signature Field tool, and drag a form field above the Custom Solutions signature line.
14 Choose Sender from the Who Needs To Sign This Field? menu. You may need to scroll up to see the option.
15 Use the Name Field, Title Field, and Date Field tools to add the remaining fields, choosing Sender from the Who Needs to Sign This Field? menu each time.
Sending the document
All the form fields are in place and recognizable by Adobe Sign, so you’re ready to send the document. You’ll send it to another person to sign for GlobalCorp and to yourself to sign for Custom Solutions. When you enter email addresses in the Adobe Sign dialog box, Adobe Sign sends the document to each address in the order they’re entered. That is, the document is sent to the first person to sign, and when it’s been signed, the document—including the first person’s signature—is sent to the second person to sign, and so on.
1 Click Send For Signature in the right-hand pane.
2 Confirm that the Statement of Work.pdf document is selected, and then click Ready To Send.
Acrobat uploads the document to the Document Cloud, and then prompts you to add recipients in the order they will sign.
3 Enter the email address of the person who should sign the document first, and press Enter or Return. For this exercise, use a colleague’s email address or an alternate address you’ve created. This person will be prompted to sign the fields that are specified for the Signer.
Note
Acrobat compares the email address you enter with your address book. If it doesn’t find the address you enter, it may prompt you to enter an address again. Click the address you already entered to proceed.
4 Just below the first signer’s email address, add the email address from which you’re sending the document. This should be the email address associated with your Adobe ID. You’ll be prompted to sign the fields specified for the Sender.
5 Customize the message if you want to, and then click Send.
Acrobat uses Adobe Sign to send the documents for signature.
Adobe Sign opens in your default browser. The document you just sent is listed in the Out For Signature category. After it’s been signed, it will be listed in the Signed category instead.
Signing the document
Adobe Sign sends email to the first address you listed. You’ll complete the form for the signer, and then complete it for the sender.
1 Log in to the email account whose address you entered first, the one that would be for the GlobalCorp representative. (If you used a colleague’s email address, ask them to access their account.)
2 Open the message with the subject line “Please sign Statement of Work.”
3 Read the message, and then click Click Here To Review And Sign Statement of Work.
Adobe Sign opens in your default browser.
4 If prompted, sign out of Adobe Sign, and then click the link in the email message again to open the document as the signer.
5 Click the yellow arrow labeled Start to go to the first field that requires your data.
6 Click the GlobalCorp signature field.
7 Type your name. If you want it to look like your manual signature, click Draw, and then draw your signature using a stylus, tablet, or touch screen. Click Image if you want to use an image or logo for your signature. (You can use an image of your written signature.) When you’re satisfied with your signature, click Apply.
Whether you select Type, Draw, or Image in the signature dialog box, you must type your name so that it is officially recorded in the Adobe Sign transaction. Conveniently, Adobe Sign automatically fills in the Name field with that information.
8 Type a title in the Title field.
9 Click the Click To Sign button at the bottom of the screen.
Now that the first person has signed, Adobe Sign sends the document to the second email address, which is yours, as the sender.
10 Log in to the email address you used to send the document (the email address associated with your Adobe ID).
11 Open the message with the subject line that reads “Your signature is required on Statement of Work.”
The subject line is different from the one in the email message you opened before, because this one is addressing the document’s sender.
12 Click the message, and then click Click Here To Review And Sign Statement of Work.
13 Adobe Sign opens with the same document. Click the yellow arrow labeled Start.
The GlobalCorp fields are completed. The Custom Solutions fields are now active.
14 Repeat steps 5-9 to sign and complete the Custom Solutions fields and to submit the signed document.
Adobe Sign sends messages to all parties informing them that the document has been signed and filed, and it attaches a PDF file of the final signed document to the message.
Creating digital signatures
Adobe Sign is available with an Acrobat, Creative Cloud, or Adobe Sign subscription. However, if you don’t have access to Adobe Sign, you can sign PDF files electronically using certificates and digital IDs. Depending on your security and communication needs, you may also prefer to use digital IDs to sign documents, as your digital ID can stamp the time, location, reason for signing, and other information as well as your signature.
For these exercises, you’ll use a self-signed digital ID, which is often adequate for signing documents. You can set the appearance of your digital signature, select your preferred signing method, and determine how digital signatures are verified in the Security preferences. You should also set your preferences to optimize Acrobat for validating signatures before you open a signed document.
Adding images to your digital signatures
First, you’ll add the company logo to your signature block.
1 Choose Edit > Preferences (Windows) or Acrobat > Preferences (Mac OS), and select Signatures from the categories on the left.
2 In the Creation & Appearance area of the dialog box, click More to open the Creation and Appearance Preferences dialog box.
3 In the Appearances section of the dialog box, click New.
Acrobat opens the Configure Signature Appearance dialog box. This is where you can personalize your digital signature by adding a graphic and specifying which information appears. The Preview pane shows the default digital signature appearance, which is text-based.
First, you’ll name the appearance of your signature and add a corporate logo to the signature block.
4 In the Title text box, type Logo.
When you name a signature appearance, use a name that is easy to associate with the contents of the appearance. You can create several digital signatures for yourself.
5 In the Configure Graphic section of the dialog box, select Imported Graphic, and click File.
6 In the Select Picture dialog box, click Browse, navigate to the Lesson08/Assets folder, and select the Local_Logo.pdf file. Supported file types are listed in the Files Of Type (Windows) or Show (Mac OS) menu. Click Open (Windows) or Select (Mac OS), and then click OK to return to the Configure Signature Appearance dialog box.
Note
Click Options to see the Show menu in Mac OS.
Now you’ll specify the information to be included in the text block of your signature. You’ll include your name, the reason for signing the document, and the date.
7 In the Configure Text area of the Configure Signature Appearance dialog box, select Name, Date, and Reason. Deselect all the other options.
8 When you’re happy with the preview of your signature block, click OK.
9 In the When Signing area of the Creation And Appearance Preferences dialog box, select View Documents In Preview Mode and Show Reasons.
10 Make sure that Adobe Default Security is selected from the Default Signing Method menu.
11 Click OK to return to the Preferences dialog box.
Selecting a verification method
Now you’ll specify how Acrobat verifies signatures.
1 In the Verification area of the Preferences dialog box, click More.
In the Signature Verification Preferences dialog box, notice that the Require Certificate Revocation Checking To Succeed Whenever Possible During Signature Verification option is selected. This ensures that certificates are always checked against a list of excluded certificates during validation.
2 Select Use The Document-Specified Method; Prompt If Unavailable (the first option under “When Verifying”). You’ll be prompted if you don’t have the necessary software when you try to open a document.
Also in the Verification Behavior area of the dialog box is a pop-up menu enabling you to choose the default method for verifying signatures. The default security method menu is dimmed when the first option is selected. You set the default method to be used when signing and encrypting documents in the Creation And Appearance Preferences dialog box.
In Windows, the Windows Integration area contains options for specifying whether all root certificates in the Windows Certificates can be trusted. We recommend that you leave the default settings in this area.
3 Click OK to close the Signature Verification Preferences dialog box.
Creating digital IDs
A digital ID is similar to a driver’s license or passport. It proves your identity to people with whom you communicate electronically. A digital ID usually contains your name and email address, the name of the company that issued your digital ID, a serial number, and an expiration date.
A digital ID lets you create a digital signature or decrypt a PDF document that has been encrypted. You can create more than one digital ID to reflect different roles in your life. For this exercise, you’ll create a digital ID for E. Grace, an employee of the fictitious Local Magazine.
1 In the Identities & Trusted Certificates area of the Digital Signatures Preferences dialog box, click More.
2 In the Digital ID And Trusted Certificate Settings dialog box, select Digital IDs in the left pane. Then click the Add ID button.
You’ll create a self-signed digital ID. With a self-signed ID, you share your signature information with other users using a public certificate. (A certificate is a confirmation of your digital ID and contains information used to protect data.) While this method is adequate for most unofficial exchanges, a more secure approach is to obtain a digital ID from a third-party provider.
3 In the Add Digital ID dialog box, select A New Digital ID I Want To Create Now. Then click Next.
If you’re working in Mac OS, skip to step 5. If you’re working in Windows, you’ll choose where to store your digital ID. The PKCS#12 Digital ID File option stores the information in a file that you can share with others. A Windows Default Certificate Digital ID is stored in the Windows Certificate Store. Because you want to easily share your digital ID with colleagues, you’ll use the PKCS#12 option.
4 Make sure that New PKCS#12 Digital File ID is selected, and click Next.
Now you’ll enter your personal information.
5 Enter the name you want to appear in the Signatures tab and in any signature field that you complete, and enter a corporate or organization name (if necessary) and an email address. We entered E. Grace for the name, Local Magazine for the Organization Name, and [email protected] for the email address. Make sure that you select a Country/Region. We used the default US - United States.
6 Choose 2048-bit RSA from the Key Algorithm menu to set the level of security. 2048-bit RSA offers more security protection than 1024-bit RSA.
You can use a digital ID to control digital signatures, data encryption (security), or both. When you use a digital ID to encrypt a PDF document, you specify a list of recipients from your Trusted Identities, and you define the recipients’ level of access to the file—for example, whether the recipients can edit, copy, or print the files. You can also encrypt documents using security policies.
For this exercise, you’ll apply the digital ID to digital signatures.
7 From the Use Digital ID For menu, choose Digital Signatures And Data Encryption, and then click Next.
Now you’ll save and safeguard your information.
8 Accept the default location for the digital ID file. Then enter Local1234;^bg as the password. Re-enter your password to confirm it. Remember that the password is case-sensitive. Be sure to make a note of your password and keep it in a safe place. You cannot use or access your digital ID without this password.
9 Click Finish to save the digital ID file in the Security folder.
Your new digital ID appears in the Digital ID and Trusted Certificates dialog box.
10 In Windows, select the digital ID to see its details. In Mac OS, double-click it to view the certificate details. When you’ve finished checking your digital ID, close the dialog box, and then click OK to close the Preferences dialog box.
Signing a document digitally with certificates and digital IDs
Because you want the graphic designers to know that the changes to this document are approved and you want them to be sure that no additional changes have been made since the time you approved it, you’ll create a visible signature field and sign the document.
First, you’ll open the draft of the travel guide document that you’ll be signing.
1 Choose File > Open. Navigate to the Lesson08/Assets folder, select Travel Guide.pdf, and click Open. Then choose File > Save As, rename the file Travel Guide1.pdf, and save it in the Lesson08 folder.
2 Click Tools to open the Tools Center, and then click Certificates in the Forms & Signatures category to open the Certificates tool.
3 Click Digitally Sign in the Certificates toolbar.
4 If an informational dialog box appears, click OK.
5 Drag to create a signature field in the area above the map.
Acrobat automatically switches into Preview mode, which analyzes the document for content that may alter the document’s appearance and then suppresses that content, enabling you to view and sign the document in a static and secure state.
Note
Acrobat switches to Preview mode because you set your preferences to view documents in Preview mode before signing. If you see the Sign Document dialog box instead, choose Edit > Preferences or Acrobat > Preferences, and then select Signatures on the left, and click More in the Creation & Appearance area. Then select View Documents in Preview Mode, and click OK.
6 In the preview toolbar across the top of the document window, click Sign Document.
7 In the Sign With A Digital ID dialog box, select the digital ID you just created, and click Continue.
8 In the Sign As dialog box, enter the password associated with the ID, Local1234;^bg.
9 Choose Logo from the Appearance menu.
Tip
Click Edit if you want to change the appearance of the signature. You can draw your signature, choose a different image, and select additional options.
10 Choose I Am Approving This Document from the Reason pop-up menu.
11 Click Sign to apply your signature, and click Save to save the signed file. Click Yes or Replace when prompted to replace the original file.
The recipient of the signed document will need your certificate to validate the digital signature.
Modifying signed documents
Now you’ll add a comment to the signed document to see how the digital signature information changes. But first you’ll look at the Signatures panel to see what a valid signature looks like.
1 Click Signature Panel in the preview toolbar to open the Signatures panel in the navigation pane. If necessary, drag the right margin of the Signatures panel so that you can see all the signature information. Expand the signature line, and expand the Signature Details entry.
Now you’ll add a note to the document and see how the addition changes the digital signature.
2 Choose Comment from the Certificates pop-up menu on the left side of the Certificates toolbar.
3 Select the Sticky Note tool (
) in the Comment toolbar.
4 Click anywhere on the document page to add a note. In the note, type Good work. Then click Post.
5 Expand the signature again in the Signatures panel. The signature status has changed with the addition of a note.
Tip
Use the Signatures panel to review the change history of a document or to track changes when a document is signed using multiple digital signature IDs.
Now you’ll validate the signature.
6 Right-click (Windows) or Control-click (Mac OS) the signature box in the document pane, and choose Validate Signature.
7 The alert box explains that although the signature is valid, a change has been made. Click Close to close the warning box.
Tip
Right-click (Windows) or Control-click (Mac OS) the signature box in the document pane, and choose Show Signature Properties to resolve any issues with the signature.
8 Right-click (Windows) or Control-click (Mac OS) the signature box in the document pane, and choose View Signed Version.
The View Signed Version option recovers the unchanged file. If a document has signatures on multiple versions of the document, for example, you can view any previously signed version of the document by selecting the signature in the Signatures panel and then choosing View Signed Version from the options menu.
9 Close both open PDF files. You do not need to save your work.
Certifying PDF files
You can also certify the contents of a PDF document. Certifying a document rather than signing it is useful if you want the user to be able to make approved changes to a document. When you certify a document and a user makes approved changes, the certification is still valid. You can certify forms, for example, to guarantee that the content is valid when the user receives the form. As the creator of the form, you can specify what tasks the user can perform. For example, you can specify that readers can fill in the form fields without invalidating the document. How-ever, if a user tries to add or remove a form field or a page, the certification will be invalidated.
Now you’ll certify a form to be sent to sponsors of a conference. By certifying the form, you ensure that the sponsors fill out the form as you designed it, with no additions or deletions to the form fields.
1 Choose File > Open, navigate to the Lesson08/Assets folder, and open the Sponsor.pdf file.
For information on the Forms message bar, see Lesson 10, “Working with Forms in Acrobat.”
2 Choose File > Properties, and click the Security tab.
The information in the Document Properties dialog box shows that no security settings and no restrictions have been applied to the document.
3 Click Cancel to close the Document Properties dialog box without making any changes.
4 Click Tools, and then click the Certificates tool to open it.
5 Click Certify (Visible Signature) in the Certificates toolbar.
6 In the dialog box that appears, click Drag New Signature Rectangle. Then click OK in the Save As Certified Document dialog box.
You’ll use the digital ID that you created earlier in the lesson to certify the file.
7 Drag anywhere in the document to create a signature field. We created a signature field in the upper left corner, below the Local logo.
8 Click the Sign Document button on the document message bar.
9 In the Sign With A Digital ID dialog box, select the digital ID to use, and click Continue. We selected E. Grace.
10 Enter the password, Local1234;^bg.
11 Choose Logo from the Appearance pop-up menu.
12 From the Reason menu, choose I Attest To The Accuracy And Integrity Of This Document.
13 From the Permitted Actions After Certifying menu, choose Annotations, Form Fill-In, And Digital Signatures.
14 Click Sign to complete the certification process.
15 Save your file as Sponsor_Cert.pdf.
16 Click Signature Panel in the document message bar, and review which actions the certification allows. You may need to expand the certification entry.
17 When you’ve finished reviewing the certification information, close the Signatures panel.
Tip
Whenever you open a certified document, you’ll see a Certification icon at the left of the message bar. You can click this icon at any time to see certification information for the document.
Signing certified documents
Now you’ll sign the document that you just certified to verify that filling in a signature field doesn’t invalidate the certification.
1 Go to page 2 in the document.
2 Select the Hand tool, and then click in the Local Signature box at the bottom of the document. Then click the Sign Document button on the document message bar.
The Sign Document dialog box opens.
3 In the Sign With A Digital ID dialog box, select your digital ID, and click Continue. We selected E. Grace.
4 Enter the password, Local1234;^bg.
5 Leave the other values, click Sign, and save the file in the same folder using the same filename. Click Yes or Replace to replace the original file.
6 Click the Signatures button in the navigation pane, and expand the certification entry marked with the ribbon icon.
Notice that the certification is still valid even though a signature has been added.
7 Choose File > Close.
Review questions
1 What is Adobe Sign?
2 Where do you change the appearance of your digital signature if you’re using a certificate?
3 Why would you want to apply password protection to a PDF file?
4 Why would you apply permissions protection to a PDF file?
Review answers
1 Adobe Sign is an electronic signature service that makes it easier for individuals and businesses to sign documents quickly and securely. If you have a Document Cloud or Creative Cloud subscription, you can use Adobe Sign to send unlimited documents for signatures, and to track and manage those documents.
2 You change the appearance of your digital signature in the Configure Signature Appearance dialog box. You can access this dialog box from the Security Preferences dialog box. You can also change the appearance of your digital signature in the Sign Document dialog box during the signing process.
3 If you have a confidential document that you don’t want others to read, you can apply password protection. Only users with whom you share your password will be able to open the document.
4 Permissions protection limits how a user can use or reuse the contents of your Adobe PDF file. For example, you can specify that users cannot print the contents of your file, or copy and paste the contents of your file. Permissions protection allows you to share the content of your file without losing control over how it is used.