Being the signature format conversion device and the thing pre-treatment equipment and the signature verification device, and the signature format conversion device which converts signature format

摘要

PROBLEM TO BE SOLVED: To provide a technique for converting the format of an electronic signature so that the signature can be verified among signature formats with different functions for acquiring a signature value from an original document.;SOLUTION: An electronic signature formed in a first signature format using a function value Enc(f(X)) as a signature value of an original document X is converted into an electronic signature of a second signature format using a function value Enc(g(Y)) as a signature value of an original document Y. To do so, a storage section stores an original document m and then an intermediate value generating section reads the original document m from the storage section, calculates an intermediate value M=f^-1(g(m)) and stores the calculated value in the storage section. Then, a signature generating section reads an intermediate value M from the storage section, calculates a signature value Enc(f(M)) of the intermediate value M conforming to the first signature format and stores the calculated value in the storage section. In addition, a format converting section generates an electronic signature of a second signature format using the signature value Enc(f(M)) as the signature value of the original document m and outputs the generated electronic signature.;COPYRIGHT: (C)2009,JPO&INPIT