| 摘要 |
PURPOSE:To provide a compatibility with a conventional password identifying system, to make the control of a cryptographic key safe and easy, to facilitate the individual addition/cancellation of a user and to invalidate a retransmittion attack, regarding a method improving the security of a network. CONSTITUTION:In a network application system identifying a user by transmitting user identification data ID and a password PW from a client and confirming the existence of the petinent ID and PW by a server, a client C ciphers the ID and PW by the open key Kp of an open key system and transmits the key Kp to a server S, and the server S takes out the ID and PW by decoding the key by his own secret key Ks. At the beginning of the identification, the server S transmits a random number R to the client C, the client C includes the ID, the PW and the received random number R and ciphers them by the open key Kp and transmits them to the server S, and the server S confirms that the decoded random number R' is the same as the random number R transmitted previously. |
