| 摘要 |
PROBLEM TO BE SOLVED: To achieve the authentication of a user by a digital signature with high security for the user of an optional terminal. SOLUTION: A server 3 enciphers a signature secret key by a password corresponding to respective clients 1, holds it in a memory 5 and also holds a public verification key in the memory 5. The client 1 shares a password cryptographic key with the server 3 by mutual communication utilizing ciphers, enciphers the password by an FEAL(fast enciphering algorithm) cryptographic key which is a password cryptographic key and transmits it to the server 3. The server 3 deciphers the password from the client 1 by the password cryptographic key, deciphers the signature secret key of the client 1 by the deciphered password, prepares the digital signature by using the signature secret key and verifies the prepared digital signature by a public key. |
