基于半陷门单向函数的公钥密码

Public key cryptosystem based on semi-trapdoor one-way function

通过引入"半陷门单向函数"的概念来构造公钥密码,与陷门单向函数不同,由于半陷门单向函数是"半可逆"的,所以不能单独用来构造公钥密码。为此本文提出了一种基于半陷门单向函数的公钥密码构造方法。并结合SSP(子集和问题)的难解性和易解性,构造了"半超递增背包向量",并基于半超递增背包向量对半陷门单向函数进行了具体实现。在此基础上,给出了一种新的公钥密码方案STOF_PKC。该方案在分类上属于背包密码,因而具有抗量子计算的潜力。

In this paper, we introduce the concept of Semi-trapdoor One-way Function （STOF） to implement the Public Key Cryptosystem （PKC）, which is different from the One-way Function. STOF is semi-invertible, so it can be directly used to implement the PKC. For this characteristic we develop a method to construct a PKC based on the STOF. Combined with the difficulty and solvability of the Subset Sum Problem （SSP）, we can construct a Semi-supper Increasing Knapsack （SSIK）. Based on SSIK a scheme of STOF is designed and realized. ON this basis, we propose two new knapsack public key schemes, STOF PKC. STOF_PKC belongs to knapsack cryptosystem, thus has the potential to resist quantum attack.