一种基于编码的公钥密码体制的参数选择研究

TCHo公钥密码体制是“Trapdoor Cipher,Hardware Oriented＆quot;的缩写,是受快速相关攻击中的陷门密码启发而得到的一种基于编码的公钥密码体制.它能抵抗量子计算机的攻击,是一种后量子密码体制.2006年,Finiasz和Vaudenay提出了TCHo公钥密码体制的一种非多项式解密时间的早期版本.2007年,Aumasson等人介绍了使用启发式算法多项式复杂度的TCHo密码体制.2013年,Alexandre和Serge在“Advances in Network Analysis and its Applications”一书中系统介绍了TCHo密码体制.它的安全性基于低重量多项式的倍式问题和带噪声的LFSR区分问题,因此参数的选择决定了密码体制的安全性与可靠性.文章详细介绍了TCHo密码体制,针对TCHo密码体制的参数选择进行了分析,指出该密码体制达到唯一译码的条件,并给出了衡量密码体制可靠性程度的计算公式,同时提出了参数选择的一种方法,从而使密码体制更可靠.

Research on Parameter Selection of a Code-based Public-Key Cryptosystem

TCHo is short for ＂Trapdoor Cipher, Hardware Oriented＂. It is a code-based public- key cryptosystem which is inspired by fast correlation attack. TCHo cryptosystem can resist the attacks from quantum computers which is a post-quantum cryptosystem. An early version was proposed in 2006 by Finiasz and Vaudenay with non-polynomial （though practical） decryption time. The later version came in 2007 with more co-authors. It reached competitive （heuristic） polynomial complexity and IND-CPA security. In 2013, Alexandre and Serge introduces the TCHo cryptosystem in Advances in Network Analysis and its Applications. The security of the cryptosystem relies on the hardness of finding a multiple polynomial with low weight and on the hardness of distinguishing between the out of the LFSR with noise and some random sources, hence, the parameter selection of this cryptosystem determines the security and reliability. This paper introduces the TCHo cryptosystem in detail and analyzes the parameter selection. This paper also points out the condition of achieving the only decoding and discusses the calculation formula for measuring the reliability level of the cryptosystem. At the same time, a method of parameter selection is presented so that the cryptosystem is more reliable.