AWS Transfer Family -SFTP Gateway : Is SSE-C for S3 supported?

Hello,

Yes, SFTP will choose whatever the default encryption is for the bucket. It can be used for SFTP with S3 as the backend storage. You need to add the usual KMS permissions to the Transfer IAM role used to access the S3 bucket with KMS-CMK.

https://docs.aws.amazon.com/transfer/latest/userguide/encryption-at-rest.html https://docs.aws.amazon.com/AmazonS3/latest/userguide/serv-side-encryption.html