Cryptanalysis of a Code-Based Identification Scheme Presented in CANS 2018

NIST recently published the first four winning algorithms from the post-quantum cryptography (PQC) standardization process that has been ongoing since 2017. The four algorithms selected are a key establishment algorithm called CRYSTALS-Kyber and three digital signature algorithms called CRYSTALS-Dilithium, FALCON, and SPHINCS+. The first two of these signature schemes are based on structured lattices and the last is a hash-based signature scheme. These future standards will be the default options for post-quantum algorithm selection in most security products. To diversify post-quantum signature standards, NIST has issued a call for submissions for signature schemes that have short signatures and fast verification before June 1, 2023. Code-based signatures schemes are promising candidates for this additional process. In this paper, we first show that the rank-based Veron's identification scheme proposed in [6] in CANS 2018 reveals information in the response step. Second, we perform an attack on the support of the error to find the secret in this scheme. Finally, we propose a secure zero-knowledge identification protocol with rank settings and a code-based signature scheme with fast verification.