Breaking HWQCS: a code-based signature scheme from high weight QC-LDPC codes

ePrint Report: Breaking HWQCS: a code-based signature scheme from high weight QC-LDPC codes

Alex Pellegrini, Giovanni Tognolini

We analyse HWQCS, a code based signature scheme presented at ICISC 2023, which uses quasi-cyclic low density parity check codes (QC-LDPC). The scheme introduces high Hamming weight errors and signs each message using a fresh ephemeral secret key rather than using only one secret key, so to avoid known attacks on QC-LDPC signature schemes.
In this paper, we show that the signatures of …

alex breaking check code eprint report errors high low message report signature