KEY MANAGEMENT METHOD, KEY CREATION METHOD, CODE PROCESSING METHOD, TRANSFER METHOD FOR DECRYPTION AUTHORITY, AND COMMUNICATION NETWORK SYSTEM

摘要

PROBLEM TO BE SOLVED: To enable a person for using electronic information to easily confirm the person as a right user and to enable only the provider of the electronic information to create and provide the conversion data to give the authority to utilize the electronic information.;SOLUTION: The code processing system comprises employing an ID-based Encryption Scheme of high convenience not requiring the check of a certificate of a public key as public information to be utilized for transfer of a decryption authority, employing bg (b is an integer) created by a creation source g of a cyclic group, determining the public information as a component of a portion of decryption secret key of a user, employing a code processing system that the user does not possess the integer b, and converting and affording the electronic data created for the purpose of transfer of the decryption authority.;COPYRIGHT: (C)2008,JPO&INPIT