## SME Disk Key Management

SME disk uses a two-level key hierarchy. An SME cluster consists of various disks that are grouped functionally into disk groups. The following is the key hierarchy:

• Master Key—Generated when a SME cluster is created. A master key is used to wrap the disk keys in the cluster. A master key is always wrapped with a password. The three security modes to store the master key are Basic, Standard, and Advanced. For more information on SME key details and the security modes, see “Configuring Key Management Operations”.

• Disk Key—Generated only when the encryption is enabled. Only when it is enabled, the disk status is Crypto. Disk keys are always wrapped with the master key.

Keys are identified using a Globally Unique Identifier (GUID) and disk keys are stored in the Cisco Key Management Center (KMC). These disk keys are encrypted using the master key.