| 摘要 |
A computer system includes a Key Certification Agency (KCA) (12), a host computer (16), and a number of remote terminals (14). The KCA (12) uses incompatible encryption processes (96, 98) to encrypt session control data and to store the data as various messages (44, 46, 48) in a user token (26). The token (26) may be removably installed in any remote terminal (14). To set up a communication session, the token uncovers one of the messages (48) using a crypto-uncovering agent which is known to the user. This message includes a remote traffic key after deciphering, but the key is never transmitted to the host. The host (16) deciphers the other messages (44, 46) and constructs a host traffic key in response to data contained therein. No plain text is transmitted during the setup or the session. |
