Signature verification api

[mechmind]

Hello. As far as I can see there are no signature verification api in this applet. I'm exploring possibilities for using smartcard for multiparty authentication schemes and want to add public key authentication to some of the methods. I.e. smartcard will hold its own private key and separate trusted public key and there will be sign method that will check that request is signed by stored public key.

I'm not a cryptography expert and I've looked to signature verification in other implementations and I'm not sure I can port them over there with enough confidence. Can you help me with this?

[dufkan]

Hi, I do not recall if there wasn't some issue with point operations needed for signature verification. I will test it when I get to it, and if everything works, I will add this functionality.

[mechmind]

Thanks a lot in advance!

I spent some time digging the other implementations and as far as I can see most of them use some sort of optimization when they precompute tables so verification process could be sped up. If I understand correctly those tables take 2-4 KiB of RAM and verification should take 2x time of signing. There is an algorithm that can perform verification without those precomputed tables and it should take 3x time of signing. I can link those repositories if you need those.

Also if I can help you with infrastructure code I would be glad to contribute.