topic Re: RT117x: use True random entropy source in i.MX RT Crossover MCUs

RT117x: use True random entropy source

mastupristi — Mon, 21 Oct 2024 15:25:46 GMT

hi,

I need a seed for my pseudo-random number generator on RT1175.

Can I use True random entropy source for this?
How can I use this?
in alternative can I use RNG?
how?

regards

Max

Re: RT117x: use True random entropy source

Kan_Li — Tue, 22 Oct 2024 05:52:29 GMT

Hi @mastupristi ,

Are you referring to CAAM's RNG4 module in RT117x or some SW implemented random number generator ? Please kindly clarify.

Have a great day,
Kan

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Re: RT117x: use True random entropy source

mastupristi — Mon, 28 Oct 2024 10:14:51 GMT

Hi @Kan_Li

Are you referring to CAAM's RNG4 module in RT117x

Yes, I'm referring to CAAM RNG

regards

Max

Re: RT117x: use True random entropy source

Kan_Li — Tue, 29 Oct 2024 02:46:32 GMT

Hi @mastupristi ,

Thanks for the clarification! The TRNG is integrated inside the CAAM module, no option to use an external True random entropy source instead.

Have a great day,
Kan

Re: RT117x: use True random entropy source

mastupristi — Tue, 29 Oct 2024 08:45:48 GMT

Hi @Kan_Li

The TRNG is integrated inside the CAAM module

this is really bad news. on the RT105x I could have extracted a random number from TRNG to use as a seed for my PRNG software algorithm.

What do you suggest I do to create a random seed for my PRNG algorithm? In other words, what else can I use as an entropy source?

no option to use an external True random entropy source instead.

what do you mean by ”external True random entropy source"?

best regards

Max

Re: RT117x: use True random entropy source

Kan_Li — Wed, 30 Oct 2024 03:38:09 GMT

Hi @mastupristi ,

Sorry for my misunderstanding! I was thinking you wanted CAAM module to use another True random entropy source instead the integrated TRNG , but for your case, if your PRNG algorithm uses DRBG algorism other than SHA256-DRBG , you may use the seed generated from CAAM's TRNG, otherwise, just directly use the output from CAMM's RNG4 with SHA256-DRBG support .

Have a great day,
Kan