ServerSideEncryptionByDefault - Amazon Simple Storage Service
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Describes the default server-side encryption to apply to new objects in the bucket. If a PUT Object request doesn't specify any server-side encryption, this default encryption will be applied. If you don't specify a customer managed key at configuration, Amazon S3 automatically creates an Amazon KMS key in your Amazon account the first time that you add an object encrypted with SSE-KMS to a bucket. By default, Amazon S3 uses this KMS key for SSE-KMS. For more information, see PUT Bucket encryption in the Amazon S3 API Reference.



Server-side encryption algorithm to use for the default encryption.

Type: String

Valid Values: AES256 | aws:kms | aws:kms:dsse

Required: Yes


Amazon Key Management Service (KMS) customer Amazon KMS key ID to use for the default encryption. This parameter is allowed if and only if SSEAlgorithm is set to aws:kms or aws:kms:dsse.

You can specify the key ID, key alias, or the Amazon Resource Name (ARN) of the KMS key.

  • Key ID: 1234abcd-12ab-34cd-56ef-1234567890ab

  • Key ARN: arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab

  • Key Alias: alias/alias-name

If you use a key ID, you can run into a LogDestination undeliverable error when creating a VPC flow log.

If you are using encryption with cross-account or Amazon service operations you must use a fully qualified KMS key ARN. For more information, see Using encryption for cross-account operations.


Amazon S3 only supports symmetric encryption KMS keys. For more information, see Asymmetric keys in Amazon KMS in the Amazon Key Management Service Developer Guide.

Type: String

Required: No

See Also

For more information about using this API in one of the language-specific Amazon SDKs, see the following: