The full ARN of the AWS Key Management Service (AWS KMS) CMK to use when encrypting the snapshots of an image during a copy operation. This parameter is only required if you want to use a non-default CMK; if this parameter is not specified, the default CMK for EBS is used. The ARN contains the arn:aws:kms namespace, followed by the region of the CMK, the AWS account ID of the CMK owner, the key namespace, and then the CMK ID. For example, arn:aws:kms:us-east-1:012345678910:key/abcd1234-a123-456a-a12b-a123b4cd56ef. The specified CMK must exist in the region that the snapshot is being copied to. If a KmsKeyId is specified, the Encrypted flag must also be set.