一种改进的基于奇偶校验码的McEliece变型方案 postprint

Abstract: McEliece public-key cryptosystem is a public-key cryptosystem based on coding theory. Its security can be reduced to the general linear code decoding problem and it can resist quantum attack. This paper proposed an improved McEliece variant scheme based on quasi-cyclic medium density parity check (QC-MDPC) code and quasi-cyclic low density parity check (QC-LDPC) code. The main improvement was that the parity check matrices of QC-LDPC code and QC- MDPC code were combined as a private key, and the concatenated codewords generated were applied to the McEliece variant scheme, and an improved decoding algorithm was given. The analysis shows that under the 80-bit security, it has small system key and low-implement complexity. In addition, this system can resist the recently proposed key recovery attacks on QC-MDPC and QC-LDPC respectively.