Loading seed to IKG

nRF54LM20A | nRF54LM20B Datasheet

Before keys can be generated, KMU must push the key generation seed used by the IKG to the SEED register and marked as valid.

To create and derive a seed the following sequence of operations are needed.

Create device unique seed
  1. Create three 128-bit random numbers using CRACEN RNG.
  2. Provision the random numbers to KMU slots 0, 1, and 2 (128 bits in each slot).
    1. SRC.DEST=CRACEN.SEED[n], where n=0, 4, and 8
    2. SRC.VALUE=random[i], where i=0,1, and 2 (random number results from CRACEN.RND operation in step 1)
Load seed from KMU to CRACEN
  1. Push the KMU slots where the seed is stored (KMU slots 0, 1, and 2).
  2. Once all SEED registers have been pushed, CRACEN locks the SEED register and validates the seed for the IKG.
Note: Any IKG key generations without valid seed (CRACEN.SEEDVALID) will fail.