Throughout this chapter, I have mentioned the Key Management Service a number of times, mainly in relation to other services using it such as S3 and RDS, as well as many other AWS services that require encryption to be performed. 

We already know that KMS uses symmetric cryptography, and this was evident when we looked at the S3 encryption mechanisms, since we saw that the very same key was used to decrypt the data that was used to encrypt the data. This is essentially symmetric cryptography. In this section, I will dive a little deeper into KMS to allow you to gain more of an understanding about the service itself.