CERTIFICATION METHOD FOR ELECTRONIC CONTENTS, SYSTEM AND MEDIUM WITH RECORDED PROGRAM

摘要

PROBLEM TO BE SOLVED: To enhance ability of the publicity and the non-alterability property of electronic contents by giving evidence to the publicity of the electronic contents existing on a network. SOLUTION: A service machine 10 chooses preferably plural witnesses from among register group 12 or a certificate generator 12a with respect to the service request of a user 11 wanting to have the testimony of the publicity of electronic contents and asks the witnesses or the certificate generator 12a to prepare the acquisition certificate of the electronic contents 14. Electronic signatures of the witnesses or the certificate generator 12a are attached to a certificate and the service machine 10 transmits this certificate to a user 11 after attaching, in addition, an electronic signature of his own.