54.5.5.12 Reseed Operation

With the Reseed operation, DRBG2 is reseeded with new entropy, and its reseed counter is reset.

New entropy always comes from DRBG1. In addition, external random entropy can be provided via PUF_DIR. The Data Source register (PUF_SRC) must be configured with 0x1.

The following table shows the number of bytes that must be provided per entropy source.

Table 54-4. Number of Bytes per Entropy Source for Reseed Operation
Entropy Source Number of Bits Number of Bytes
DRBG1 384 48
Entropy via PUF_DIR 1024 128