We propose a rank metric code-based signature scheme constructed via the Schnorr approach. We define a new problem in rank metric coding theory, namely the Rank Vector Decomposition problem and analyze its solving complexity. The hardness of our signature scheme is based on the Rank Syndrome Decoding problem, Rank Support Basis Decomposition problem and Rank Vector Decomposition problem. We also give detailed analysis for the structural security of our signature scheme. Then, we provide parameters for our constructed signature scheme and compare our scheme with other existing secure rank metric signature schemes. Our signature scheme requires only public key size of 443 bytes and signature size of 4.03 kilobytes for 128-bit security level.

We propose a rank metric code-based signature scheme based on the rank syndrome decoding problem, and analyze its security. We also provide necessary conditions for being MRD codes. Then, we provide parameters for the constructed signature scheme based on random linear codes constructed from Cauchy matrix. We also compare the signature scheme with those code-based signature schemes submitted to the NIST call for Post-Quantum Cryptography Standardization. The comparison shows that our signature scheme performs better than those schemes in terms of public key size and secret key size. The public key size and secret key size of our signature scheme are more than 3 times and 40 times smaller than those of the signature schemes submitted to the NIST call for Post-Quantum Cryptography Standardization.