Cryptographic communication system and communication terminal apparatus and cryptographic communication program and cryptographic communication method

摘要

PROBLEM TO BE SOLVED: To provide a communication terminal device which has neither user's confidential information nor biometric authentication function, and which is safe even when the device is lost or stolen.;SOLUTION: IP telephones 100A and 100B respectively read and store fingerprint information FPA of a user A and fingerprint information FPB of a user B by fingerprint sensors 1131a and 1131b, and transmit the fingerprint information to an SIP server 300. The SIP server 300 stores fingerprint checking data, checks the fingerprint checking data with received fingerprint information, authenticates users A and B, and returns the FPA to the IP telephone 100B and the FPB to the IP telephone 100A at successful authentication. The IP telephone 100A generates a public key K based on the stored FPA and the received FPB, and the IP telephone 100B generates the public key K based on the stored FPB and the received FPA. The IP telephones 100A and 100B perform cipher communication by the generated public key K, and delete the public key K and the fingerprint information stored when the cipher communication ends.;COPYRIGHT: (C)2008,JPO&INPIT