bucketKeyEnabled

Specifies whether Amazon S3 should use an S3 Bucket Key for object encryption with server-side encryption using KMS keys (SSE-KMS).

S3 Bucket Keys are always enabled for GET and PUT operations in a directory bucket and can’t be disabled. S3 Bucket Keys aren't supported, when you copy SSE-KMS encrypted objects from general purpose buckets to directory buckets, from directory buckets to general purpose buckets, or between directory buckets, through CopyObject, UploadPartCopy, the Copy operation in Batch Operations, or the import jobs. In this case, Amazon S3 makes a call to KMS every time a copy request is made for a KMS-encrypted object.