AWS Key Management Service (KMS) now supports tagging of keys

AWS Key Management Service (KMS) is a managed service that makes it easy for you to create and control the encryption keys used to encrypt your data. Starting today, you can tag KMS keys to better organize how keys are used, and to track your KMS costs in the cost allocation report more easily. You can tag a key at the time of key creation or after the key is created.
Quelle: aws.amazon.com