kmsKeyIdentifier

The identifier of the KMS customer managed key for EventBridge to use, if you choose to use a customer managed key to encrypt this connection. The identifier can be the key Amazon Resource Name (ARN), KeyId, key alias, or key alias ARN.

If you do not specify a customer managed key identifier, EventBridge uses an Amazon Web Services owned key to encrypt the connection.

For more information, see Identify and view keys in the Key Management Service Developer Guide.