Patent ID: 8184813
Filing Date: 2012-05-22
Classification: H04L

Abstract:
1. An encryption key generation device which generates encryption keys by (i) a first trapdoor-equipped unidirectional replacement and a second trapdoor-equipped unidirectional replacement which are compatible and publicly disclosed, (ii) a first unidirectional reverse replacement which is a reverse replacement of the first trapdoor-equipped unidirectional replacement and which is not publicly disclosed, and (iii) a second unidirectional reverse replacement which is a reverse replacement of the second trapdoor-equipped unidirectional replacement and which is not publicly disclosed, said device comprising: individual encryption key generation means for generating a plurality of different individual encryption keys, for encrypting and decrypting input data, by subjecting a predetermined initial encryption key at least once to the first unidirectional reverse replacement and at least once to the second trapdoor-equipped unidirectional replacement; and master encryption key generation means for generating a master encryption key, for regenerating the individual encryption keys, by subjecting any one of the individual encryption keys generated by said individual encryption keys generation means at least once to at least one of the first unidirectional reverse replacement and the second unidirectional reverse replacement, wherein the first trapdoor-equipped unidirectional replacement is an RSA function x