| 摘要 |
<p>A transaction terminal (10) transmits transaction information plus an encrypted PIN (personal identification number) to its associated acquirer station (12) the PIN being encrypted using a session key KS1 extracted at the terminal and decrypted using a first master key. The acquirer station sends on the message, with KS1 encrypted in a second master key, to a net work switch which routes the message to the appropriate issuer station (20) with KS1 re-encrypted in a third master key. For avoidance of errors messages are preferably accompanied by authentication codes compared therefrom. The data processor at the issuer station verifies the transaction and returns an authorisation code (or denial code) via the switch (16) and acquirer station (12) to the originating terminal. The acquirer station depends to the chain message a new session key KS2 encrypted using the first master key for use as the session key KS1 in the next transaction.</p> |
