Cryptanalysis of a code-based full-time signature

We present an attack against a code-based signature scheme based on the Lyubashevsky protocol that was recently proposed by Song, Huang, Mu, Wu and Wang (SHMWW). The private key in SHMWW contains columns coming part from identity matrix random matrix. existence of two types leads to strong bias distribution set bits produced signatures. Our exploits such recover bunch collected provide theoretical analysis along with experimental evaluations, we show as few 10 signatures are enough be for successfully recovering key. As previous attempts adapting Lyubashevsky’s case cryptography, is thus proved unable acceptable security. This confirms devising secure schemes efficiency comparable other post-quantum solutions (e.g., lattices) still challenging task.