Explanation: Server-side encryption is about protecting data at rest. Server-side encryption with Amazon S3-managed encryption keys (SSE-S3) employs strong multi-factor encryption. Amazon S3 encrypts each object with a unique key. As an additional safeguard, it encrypts the key itself with a master key thatit regularly rotates. http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingServerSideEncryption.html