A company has decided to migrate sensitive documents from on-premises data centers to Amazon S3. Currently, the hard drives are encrypted to meet a compliance r...

A company has decided to migrate sensitive documents from on-premises data centers to Amazon S3. Currently, the hard drives are encrypted to meet a compliance requirement regarding data encryption. The CISO wants to improve security by encrypting each file using a different key instead of a single key. Using a different key would limit the security impact of a single exposed key.
Which of the following requires the LEAST amount of configuration when implementing this approach?