3.5.6 Get Key Operation

The Get Key operation derives a key from the intrinsic PUF key and the provided context, scope, and length. The key is provided to the defined destination interface. Depending on the state of the PUF module, the allowed destinations may be limited as described in Context Specification for Key Operations. When an invalid destination is defined, the command is rejected.

Bits 3:0 of the user context 0 may be used to set a Key Index when the key is transferred to the HSM Lite module. When the key is returned in an output parameter, the value can be used to transfer the key to a specific process or function. These bits can be easily added to the user context 0 with the DRV_PUF_CreateUserContext0 function in the PUF driver.