###  Introduced KMS v2

Introduce KMS v2alpha1 API to add performance, rotation, and observability improvements. Encrypt data at rest (ie Kubernetes `Secrets`) with DEK using AES-GCM instead of AES-CBC for kms data encryption. No user action is required. Reads with AES-GCM and AES-CBC will continue to be allowed. See the guide [Using a KMS provider for data encryption](https://kubernetes.io/docs/tasks/administer-cluster/kms-provider/) for more information.

  * Add secretbox and AES-CBC encryption modes to at rest encryption. AES-CBC is considered superior to AES-GCM because it is resistant to nonce-reuse attacks, and secretbox uses Poly1305 and XSalsa20. ([#46916](https://github.com/kubernetes/kubernetes/pull/46916), [@smarterclayton](https://github.com/smarterclayton))

* Bug fixes:

* Add secretbox and AES-CBC encryption modes to at rest encryption.  AES-CBC is considered superior to AES-GCM because it is resistant to nonce-reuse attacks, and secretbox uses Poly1305 and XSalsa20. ([#46916](https://github.com/kubernetes/kubernetes/pull/46916), [@smarterclayton](https://github.com/smarterclayton))