Blind Signature Scheme Based on QC-MDPC Codes

In this paper, we construct a new blind signature scheme based on Quasi-cyclic Moderate Density Parity-Check (QC-MDPC) codes. This scheme is realized by using QC-MDPC codes and bit flipping decoding algorithm under Courtois-Finiasz-Sendrier (CFS) signature system. The security of our blind signature scheme relies on the difficulty of the syndrome decoding problem in coding theory, which has been shown to be NP-complete and secure against quantum attacks. This scheme greatly reduces the public key size as well as the signature length compared to other code-based blind signature schemes. To achieve security level 2^80, the public key size in our blind signature scheme is 4801bits and the signature length is 1029.05bits, which are better than almost other schemes.