The vCenter Server must have new Key Encryption Keys (KEKs) reissued at regular intervals for vSAN encrypted datastore(s).

The KEK for a vSAN encrypted datastore is generated by the Key Management Server (KMS) and serves as a wrapper and lock around the Disk Encryption Key (DEK). The DEK is generated by the host and is used to encrypt and decrypt the datastore. A shallow rekey is a procedure in which the KMS issues a new KEK to the ESXi host, which rewraps the DEK but does not change the DEK or any data on disk. This operation must be done on a regular, site-defined interval and can be viewed as similar in criticality to changing an administrative password. If the KMS is compromised, a standing operational procedure to rekey will put a time limit on the usefulness of any stolen KMS data.