CRYPTOGRAPHIC COMMUNICATION TERMINAL, CRYPTOGRAPHIC COMMUNICATION CENTER DEVICE, CRYPTOGRAPHIC COMMUNICATION SYSTEM, AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To securely and effectively update a new cryptographic algorithm via a network even in the case that the cryptographic algorithm itself is not disclosed. ;SOLUTION: This cryptographic communication terminal is provided with a communication means (2) for receiving a ciphered cryptographic algorithm and its digital signature, a cryptographic algorithm storage part (5) for storing the ciphered cryptographic algorithm received by the communication means together with the digital signature thereof, an algorithm key information storage part (3) for storing an algorithm decoding key for decoding the ciphered cryptographic algorithm, a signature verifying means (8) for verifying the digital signature regarding the ciphered cryptographic algorithm received by the communication means, and a cryptographic algorithm decoding means (9) for decoding the ciphered cryptographic algorithm justified by the signature verification means from a verification result by the algorithm decoding key in the algorithm key information storage part and providing it for cryptographic communication.;COPYRIGHT: (C)2001,JPO