The first line of the article reads otherwise, that it's using the AES256 option, which does work cross-account without KMS permissions. > Amazon S3 now automa

The first line of the article reads otherwise, that it's using the AES256 option, which does work cross-account without KMS permissions. > Amazon S3 now automatically applies S3 managed server-side encryption (SSE-S3) as a base level of encryption to all new objects added to S3