boltlabs-inc / tss-ecdsa

An implementation of a threshold ECDSA signature scheme
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Check modulus size assumption in pi fac #502

Open marsella opened 10 months ago

marsella commented 10 months ago

Some of the weirdness we uncovered while addressing #113 and #465 is due to an assumption in the last line of Fig 28:

The proof guarantees that each p, q > 2^ell (assuming 2^(2ell + ε ≈ √N0).

We don't check that assumption in the proof itself. In #466 we aim to check that assumption in at least one place, but it seems like it's worth checking in the proof verification itself as well, so we don't rely on it having been handled elsewhere.