A study on construction of computationally independent one-way functions and their application to cryptographic protocol

从离散对数问题的艰难性出发，我们成功地构造了一对计算独立的显式单向函数。我们的证明论点是基于平方Deffie-Hellmann问题。这一主要结果发表在2013年密码学与信息安全研讨会上。此外，我们还有一位联合研究员，赵云雷教授（中国复旦大学），当樱井Kouichi访问安全实验室时，他正在新加坡管理大学访问。他提出函数的非延展性和我们计算独立的单向函数的概念之间存在某种关系。赵云雷教授受NICT邀请赴日研究，于2012年9月起赴九州大学进行为期6个月的访问，并就该课题进行了包括密码密钥交换协议在内的联合研究，部分研究成果发表在2013年密码学与信息安全研讨会上。

We succeed to construct an explicit pair ofcomputationally independent one-way functions from the hardness of the discrete logarithm problem. Our proof argument is based on the square Deffie-Hellmann problem. This main result is presented in Symposium of Cryptography and Information Security 2013 . Also we get a joint researcher, Prof. Yunlei ZHAO (Fudan Univ. China) who was visiting in Singapore Management Univ. when Kouichi SAKURAI has visited the security lab. His suggestion issome relationship between non-malleability of functions and our notion of computationally independent one-way functions. Prof. Yunlei ZHAO has visited Kyushu Univ. from Sept 2012 for 6 months thanks to NICT’s inviting program of foreign researcher to Japan, and we perform joint research on this topic including cryptographic key exchange protocols, a partial result of which is presented also in Symposium of Cryptography and Information Security 2013.