What does S3 replication with encryption ensure?

S3 replication with encryption ensures that data is protected throughout the entire lifecycle, addressing both the security of data during transfer and its storage. When data is replicated in Amazon S3, encryption ensures that the data is encrypted while it is being transferred from the source bucket to the destination bucket, which secures it against interception during transit.

Moreover, once the data reaches the destination bucket, it is stored in an encrypted format, meaning that even if there were unauthorized access to the physical storage in the destination, the actual data would remain protected. This dual layer of protection—encryption in transit and encryption at rest—provides a robust security mechanism that helps comply with data protection regulations and standards.

This answer captures the essence of data security practices within S3, illustrating the importance of maintaining encryption throughout the data's movement and storage without compromising accessibility or performance.