基于QC-LDPC码的Niederreiter公钥密码体制

Niederreiter public-key cryptosystem based on QC-LDPC

提出基于准循环低密度奇偶校验(QC-LDPC)码构造的Niederreiter公钥密码体制。由于QC-LDPC的校验矩阵具有稀疏和分块循环的特性,且QC-LDPC的纠错能力大,与以往基于纠错码构造的公钥密码体制相比,该体制密钥量大大减少,提高了传信率。同时引入对角形式的可逆变换矩阵Q,通过线性变换产生新的校验矩阵H',隐藏了码字的校验矩阵,可以抵消矩阵H'稀疏易攻击的弱点,增加了体制的安全性。并且通过对现有的攻击方法分析,证明了体制的安全性。

A Niederreiter public-key cryptosystem based on Quasi-Cyclic Low-Density Parity Check（QC-LDPC） Code was proposed.As the check matrix of QC-LDPC is sparse,and has the structure of circulative blocks and high error correction capability,compared with other public-key cryptosystem,the key sizes of the new cryptosystem were reduced and transmission rate was improved.A new parity-check matrix was mapped by invertible transformation matrix Q with diagonal form.The sparse characteristic of H′ is countervailed.Through analyzing the existing attacking methods,security of the cryptosystem has been confirmed.