crypto: ecc - constant-time modular inversion?
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Quoted 4 lines · Erwin Pawliczek
Hello,
vli_mod_inv()incrypto/ecc.cis currently responsible for modular inversion, it is currently a binary greatest common denominator loop where the iteration count depends on input. I'd like to replace it with a constant time algorithm, this one: https://eprint.iacr.org/2019/266
Is it used outside of ECDSA signature verification (with secret input)? If no, the replacement needs to be faster to justify the change
Quoted 7 lines
It runs a fixed number of divsteps for a given operand size, independent of input.
I already started working on a replacement, please let me know if this is something you'd be interested in.
Thanks,
Erwin
Ignat