CIPHER COMMUNICATING METHOD, AND CIPHER COMMUNICATION SYSTEM AND ID CARD SUITABLE TO IMPLEMENTATION OF THE SAME METHOD

摘要

PROBLEM TO BE SOLVED: To provide the cipher communicating method which enables a large number of unspecified people to have a cipher communication by making good use of an open key system. ;SOLUTION: The issuing organization 1 of a country which issues nation number cipher ID cards (SSID card 5) unitarily sets secret keys 2 of, for example, RSA code which is the standard of a cipher communication based upon a nation number system and open keys 3 for nation individuals. Then the secret key 2 is written in, for example, a cipher LSI 4 and the SSID card 5 in which the LSI is built is issued to a user. At the same time, the open key 3 of the user of the SSID card 5 is made open to the public through, for example, a telephone directory, a CD-ROM, etc. Here, the same number is used as both the nation number and open key 3.;COPYRIGHT: (C)1998,JPO