# Check value in CloudHSM CLI
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The *check value* in CloudHSM CLI is a 3-byte hash or checksum of a key that is generated when the HSM imports or generates a key. You can also calculate a check value outside of the HSM, such as after you export a key. You can then compare the check value values to confirm the identity and integrity of the key. To get the check value of a key, use [key list](cloudhsm_cli-key-list.md) with the verbose flag.

AWS CloudHSM uses the following standard methods to generate a check value:
+ **Symmetric keys**: First 3 bytes of the result of encrypting a zero-block with the key.
+ **Asymmetric key pairs**: First 3 bytes of the SHA-1 hash of the public key.
+ **HMAC keys**: KCV for HMAC keys is not supported at this time.