Questions about the random number generator function

[Derek_Yoon]

Hello teams.

Hope all is well

I saw an NXP engineer's response to a TRNG related question on this board that "TRNG operates internally to generate the seed from which the PRNG is built."

So, does that mean there is no need to input a separate seed value to generate a random number?

Ps :  I know that when using the DRBG algorithm, it need to input a seed with a certain entropy. Are the DRBG algorithm and PRNG different concepts?

[lukaszadrapa · Accepted solution]

Hi @Derek_Yoon 

Are we talking about CSEc on S32K1? It's given by SHE specification. Initial seed is generated by CMD_INIT_RNG command. Then you can generate random numbers while it is not necessary to reseed. The only additional thing you can do in runtime is to run CMD_EXTEND_SEED command to supply 128 bit of entropy. You can call this command whenever additional entropy is needed.

Regards,
Lukas

[Derek_Yoon]

That's right, I was asking about the CSEc on the S32K. Thanks for the help! My question is all cleared up