CIPHERING METHOD, CIPHERING COMMUNICATION METHOD, CIPHERED SENTENCE GENERATOR, CIPHERING COMMUNICATION SYSTEM AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide a ciphering system having a public key ciphering system which is capable of conducting high speed ciphering/deciphering processes and is strong in coping with a difference key attack.;SOLUTION: A plain sentence X is divided into plural one bit divided plain sentences. Then, plural one bit converted and divided sentences having no complementary relationship with the divided sentences (are not simple bit reversal) are generated from the plural divided plain sentences. Then, a ciphered sentence C is generated by the sum of the inner products of the divided plain sentences and one set of the public keys beforehand prepared in a database 10 and the inner products of the converted and divided plain sentences and the other set of the public keys beforehand prepared in the database 10.;COPYRIGHT: (C)2002,JPO