VoteMe

hitcon2026

Task: a custom ECDHE TLS gateway in front of a snarkjs PLONK voting API leaks a capture with all ballots but private votes. Solution: exploit the 2^16 curve cofactor to leak scalar mod 2^16 and rebuild the shared MT19937 state, decrypt TLS, then recover each vote from the uuid->Math.random->ChaCha blinder chain and replay the proof.