| 摘要 |
<p>This invention aims to enable sending and receiving of a security mail to be ensured at a high security level using a relatively simple series of procedures. Respective users (A, B, ...) on-line register personal information for authentication peculiar to the respective users at a key center which manages, in turn, the personal information transmitted to the key center. When a message is transmitted from the user A to the user B, the user A on-line transmits a communication key to the key center. The key center KC on-line transmits this encrypted communication key addressed to the user B to the user B. Then the user A on-line transmits the message encrypted on the basis of the communication key directly to the user B. The user B decodes the encrypted messaged received from the user A using the communication key having been delivered from the key center KC. <IMAGE></p> |
