Encryption key distributed generation method, signature generation and verification method, encryption key distributed generation device, the signature generation and verification system, encryption key distributed generation program and signature generation and verification program were each recorded computer-readable recording medium

摘要

PROBLEM TO BE SOLVED: To provide a method and a device capable of generating a distributed cryptographic key at a higher speed as compared with the conventional distributed key generating method, and to provide a recording medium in which the program therefor is recorded. ;SOLUTION: This distributed cryptographic key generating device in an enciphering device has i-pieces (i=1, 2,..., k) of cryptographic key generating means (i) for generating the cryptographic keys by setting p2q as a 1st public key (n) with pi and qi (where p= pi and q= qi) obtained by distributing two prime numbers (p) and (q) to a server (i) as a 1st distributed secret key, setting (e) satisfying ed = 1 mod L (where L=p(p-1)(q-1) as a 2nd public key and setting di (where d= di) obtained by distributing (d) to the server (i) as a 2nd distributed secret key, and obtains cipher text C based on C=Me (mod n) from plaintext M by using the 1st and 2nd public keys (n) and (e) generated by the means (i). Each of cryptographic key generating means (i) is provided with a random number generating means for respectively generating two random numbers pi and qi and a public key candidate generating means for generating candidates N=(i1, 2,..., kpi)2 (i1, 2,..., kqi) for the 1st public key (n) by using a BGW protocol.;COPYRIGHT: (C)2001,JPO