Quasi- similar type one side the signature manner which uses tropistic function, the device and signature verification manner,

摘要

PROBLEM TO BE SOLVED: To provide an electronic signature method which is not broken even when a quantum computer is realized by constituting electronic signature by using a homomorphic unidirectional function which is not based on number theory problems such as a problem of factorization into prime factors and a problem of discrete logarithms.;SOLUTION: When it s defined that f:A→B is a homomorphic unidirectional function (f(a×b)=f(a)×f(b) is satisfied, the function f can be easily calculated but the calculation of a function f^-1 is difficult) and H:{0,1}*→{0,1}^k (k is a security parameter) is a hash function, the electronic signature method is provided with a means for selecting x_i element of A (i=1,..., k) at random, secretly storing the selected value as a secret key and disclosing X_i=f(x_i) element of B (i=1,..., k) as a public key and a means for selecting r_i element of A (i=1,..., k) at random for a message m, calculating (e₁,..., e_k)=H(f(r₁),..., f(r_k), m), calculating y_i=r_i×x_i^ei, and outputting signature (f(r₁),..., f(r_k), y₁,..., y_k) for the message m.;COPYRIGHT: (C)2004,JPO