The KMU — Key management unit is designed to securely transfer symmetric encryption keys directly into the dedicated write-only key registers of the AES and CHACHA cryptographic engines upon request from the CPU.
Pushing a symmetric key value stored in a KMU key slot into either the AES or CHACHA engine will replace the need for software to write a session key in clear-text into registers AES_KEY_0[n] (n=0..7) and AES_KEY_1[n] (n=0..7) for 128/256 bits AES keys or registers CHACHA_KEY[n] (n=0..7) for 128/256 bits CHACHA keys.
The symmetric key value pushed from a KMU key slot into the AES or CHACHA engine will be retained until CRYPTOCELL is disabled or the device is reset.