Exploiting Signature Leakages: Breaking Enhanced pqsigRM
Thomas Debris-Alazard, Pierre Loisel, Valentin Vasseur · 2024
Enhanced pqsigRM is a code-based hash-and-sign scheme proposed to the second National Institute of Standards and Technology call for post-quantum signatures. The scheme is based on the (U, U + V) -construction and it enjoys remarkably small signature lengths, about 1KBytes for a security level of 128 bits. Unfortunately we will show that signatures leak information about the underlying (U, U + V) -structure. It allows to retrieve the private-key with 100, 000 signatures.