Request Amazon S3 to encrypt your object before saving it on disks in its data centers and then decrypt it when you download the objects.
SSE-S3: uses one of the strongest block ciphers available, 256-bit Advanced Encryption Standard (AES-256) GCM to encrypt your data
SSE-KMS: Uses a key generated and managed by AWS KMS
SSE-C: uses a key generated and managed by you ( the client/customer)