KEY DISTRIBUTION METHOD AND KEY DISTRIBUTION SYSTEM BASED ON IDENTIFICATION INFORMATION OF USER CAPABLE OF UPDATING KEY

摘要

PROBLEM TO BE SOLVED: To provide an electronic signature method and an electronic signature system based on an ID which enables the updating of a key.;SOLUTION: This electronic signature system is composed of a communication network 1, a database 10, a key management server 20, a user terminal 30a, and a user terminal 30b. The database 10 stores the number of times of updating signatures key issued for the terminals 30a, 30b and a group of functions, and discloses the number of times of updating signature keys and the group of stored functions to the terminals 30a, 30b. The server 20 issues signature keys or verification keys to the terminals 30a, 30b, and manages the number of times of updating signature keys or the group of functions used for generating the signature keys which have been issued to the terminals 30a, 30b.;COPYRIGHT: (C)2004,JPO