TRANSACTION TERMINAL SYSTEMS PROVIDED WITH POTENTIAL USER AUTHENTICATION

摘要

A transaction terminal system includes a user accessible terminal coupled by a message transmission link to a remote controller and incorporates a potential user authentication combination based on an encryption check and arranged so that the crictical encryption key is not resident nor is transmitted overtly to the user accessible terminal. The potential user enters into the terminal a transaction identifier and a first message from a card together with a second memorized message. The two messages are combined in the terminal to provide a key which is used to encrypt the transaction identifier. The identifier is transmitted to the controller, with and without encryption by their particular key where the identifier is encrypted by a key stored in the controller and a comparison is performed between the two encrypted forms to test for validity of the input and an acceptance signal is transmitted back to the terminal. Other tests can be performed as to the validity of the transaction and the status of the terminal and the transmission can be overlayed by levels of encryption and decryption. The controller may form part of a host computer or of an intermediate node or both and authentication may be performed at the node when the host computer is off-line.