Computer-readable recording medium, contract creation system, contract verification system, and final cipher creation system

摘要

A computer-readable recording medium records a contract creation program for creating a contract image of a contract executed by parties each having private key. The program causes a computer to perform steps of: creating, for each party, a signature image of handwritten signature; creating, for each party, signature identification information for identifying the signature image; creating text identification information for identifying contract body text; creating, for each party, an intermediate cipher by enciphering the signature identification information of the party and the text identification information with the private key of the party; creating, for each party, a final cipher by enciphering the signature identification information of the party and the intermediate ciphers of all other parties with the private key of the party; creating an optical mark from each final cipher; and creating the contract image including the text, the signature images, and the optical marks disposed in predetermined columns.