CIPHERING METHOD, CIPHERED COMMUNICATION METHOD, AND CIPHERTEXT GENERATING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a new ciphering method for an open key ciphering system whose safety is based upon the arbitrary selection of one combination of open keys out of very many combinations of open keys. ;SOLUTION: Multiple open keys having random number terms embedded by divided plaintexts are prepared in a database 10 and arbitrary open keys are selected out of the prepared open keys for respective divided plaintexts and used to generate a ciphertext C. Here, the safety is based upon the free section of a desirable combination of open keys out of many open keys, in other words, many combinations of open keys which can be selected.;COPYRIGHT: (C)2001,JPO