General availability: Customer managed key encryption for Enterprise tier caches

Now generally available, Enterprise and Enterprise Flash tier caches can use customer managed keys (CMK) to control encrypted access to the operating system and persistence disk attached to their Enterprise tier cache instances. This ensures that the RDB or AOF files created from Redis persistence or export features are encrypted at rest with a compliant and secure key that you can control. Keys can be stored using Azure Key Vault and user-assigned managed identity is used for authorization. [Learn more](https://aka.ms/rediscmk). * Azure Cache for Redis * Features * [ Azure Cache for Redis](https://azure.microsoft.com/en-gb/products/cache/)