针对现有Niederreiter公钥密码方案容易遭受区分攻击和信息集攻击(ISD)的现状,提出一种改进的Niederreiter公钥密码方案。首先,对Niederreiter公钥密码方案中的置换矩阵进行了改进,把原有的置换矩阵替换为随机矩阵;其次,对Niederreiter...针对现有Niederreiter公钥密码方案容易遭受区分攻击和信息集攻击(ISD)的现状,提出一种改进的Niederreiter公钥密码方案。首先,对Niederreiter公钥密码方案中的置换矩阵进行了改进,把原有的置换矩阵替换为随机矩阵;其次,对Niederreiter公钥密码方案中的错误向量进行了随机拆分,隐藏错误向量的汉明重量;最后,对Niederreiter公钥密码方案的加解密过程进行了改进,以提高方案的安全性。分析表明,改进方案可以抵抗区分攻击和ISD;改进方案的公钥量小于Baldi等提出的方案(BALDI M,BIANCHI M,CHIARALUCE F,et al.Enhanced public key security for the Mc Eliece cryptosystem.Journal of Cryptology,2016,29(1):1-27)的公钥量,在80比特的安全级下,改进方案的公钥量从原方案的28 408比特降低到4 800比特;在128比特的安全级下,改进方案的公钥量从原方案的57 368比特降低到12 240比特。作为抗量子密码方案之一,改进方案的生存力和竞争力增强。展开更多
TCHo公钥密码体制是"Trapdoor Cipher,Hardware Oriented"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T...TCHo公钥密码体制是"Trapdoor Cipher,Hardware Oriented"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。展开更多
Multivariate Public Key Cryptography （MPKC） has intensively and rapidly developed during the past three decades. MPKC is a promising candidate for post-quantum cryptography. However, designing it is universally rega...Multivariate Public Key Cryptography （MPKC） has intensively and rapidly developed during the past three decades. MPKC is a promising candidate for post-quantum cryptography. However, designing it is universally regarded as a difficult task to design a secure MPKC foundation scheme, such as an encryption scheme and key exchange scheme. In this work, we investigate the security of a new public key cryptosystem that is based on the Morphism of Polynomials （MP）. The public key cryptosystem proposed by Wang et al. （Wuhan University, China） comprises a key exchange scheme and encryption scheme. Its security can be provably reduced to the hardness of solving a new difficult problem, namely, the Decisional Multivariate Diffie Hellman （DMDH） problem. This problem Js a variant of the MP problem, which is difficult to solve by random systems. We present a proposition that reduces the DMDH problem to an easy example of the MP problem. Then, we propose an efficient algorithm for the Key Recover Attack （KRA） on the schemes of the public key cryptosystem. In practice, we are able to entirely break the cryptosystem＇s claimed parameter of 96 security levels in less than 17.252 s. Furthermore, we show that finding parameters that yield a secure and practical scheme is impossible.展开更多
文摘针对现有Niederreiter公钥密码方案容易遭受区分攻击和信息集攻击(ISD)的现状,提出一种改进的Niederreiter公钥密码方案。首先,对Niederreiter公钥密码方案中的置换矩阵进行了改进,把原有的置换矩阵替换为随机矩阵;其次,对Niederreiter公钥密码方案中的错误向量进行了随机拆分,隐藏错误向量的汉明重量;最后,对Niederreiter公钥密码方案的加解密过程进行了改进,以提高方案的安全性。分析表明,改进方案可以抵抗区分攻击和ISD;改进方案的公钥量小于Baldi等提出的方案(BALDI M,BIANCHI M,CHIARALUCE F,et al.Enhanced public key security for the Mc Eliece cryptosystem.Journal of Cryptology,2016,29(1):1-27)的公钥量,在80比特的安全级下,改进方案的公钥量从原方案的28 408比特降低到4 800比特;在128比特的安全级下,改进方案的公钥量从原方案的57 368比特降低到12 240比特。作为抗量子密码方案之一,改进方案的生存力和竞争力增强。
文摘TCHo公钥密码体制是"Trapdoor Cipher,Hardware Oriented"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。
文摘Multivariate Public Key Cryptography （MPKC） has intensively and rapidly developed during the past three decades. MPKC is a promising candidate for post-quantum cryptography. However, designing it is universally regarded as a difficult task to design a secure MPKC foundation scheme, such as an encryption scheme and key exchange scheme. In this work, we investigate the security of a new public key cryptosystem that is based on the Morphism of Polynomials （MP）. The public key cryptosystem proposed by Wang et al. （Wuhan University, China） comprises a key exchange scheme and encryption scheme. Its security can be provably reduced to the hardness of solving a new difficult problem, namely, the Decisional Multivariate Diffie Hellman （DMDH） problem. This problem Js a variant of the MP problem, which is difficult to solve by random systems. We present a proposition that reduces the DMDH problem to an easy example of the MP problem. Then, we propose an efficient algorithm for the Key Recover Attack （KRA） on the schemes of the public key cryptosystem. In practice, we are able to entirely break the cryptosystem＇s claimed parameter of 96 security levels in less than 17.252 s. Furthermore, we show that finding parameters that yield a secure and practical scheme is impossible.
