Is there a reason to use STSafe-a100 with STM32WB55?

[YWor.1]

Hi.

I am working on STM32WB55 and I need to implement a digital signature verification function. I know this MCU has PKA for this purpose, but I also found that ST produce STSafe-a100 module, that in my understanding does about the same, at least for my use(ECDSA).

So the question is, what is the difference between those module and do I need this STSafe-a100 in my device?

Appreciate any tip.

Thanks.

[Benjamin BARATTE]

Hi @YWor.1​ 

Thanks for you request.

The added value of the STSAFE-A solution is to have smartcard grade Secure Element to manage ECC private key to generate ECDSA signature and a secure storage.

In your use case, you just need to verify an ECDSA signature if I have understood well, therefore the STSAFE-A will act as a crypto accelerator like the PKA from the STM32WB55.

The added value of the STSAFE-A in your use case could be to store in a secure way the public key you use for ECDSA verification. In that case, the STSAFE-A could guarantee the integrity of the public key if set in a read-only region.

Best Regards,

Benjamin