Abstract: The system provides both electronic signature and message verification with a minimum of excess coding information on an instantaneous basis and is easily restartable in a store and forward environment. The system is based on the concept of a vault or central authority. The vault is in essence a physically secured Authenticator designed as a hardware automation which is not under control of any operating system. The system is a terminal based network wherein all terminals or users may communicate directly or through a central CPU. All secure electronic signature verification transactions must be transacted through the central facility which includes said vault. The vault and all terminals include an identical key-controlled block-cipher cryptographic facility wherein each user at a terminal has access only to his own key and wherein the vault has access to all user keys.

Abstract: An electronic funds transfer system wherein it is required that a bank be reasonably guaranteed that the two parties to a retail transaction (i.e., a person and a retailer) agree on the transaction before the funds transfer takes place. The message including the transaction information is encrypted by the person using a unique encryption key (K.sub.P) stored in a highly secure storage location in his own personal portable transaction device (XATR) and his data storage and transfer card (DSTC) and this first encrypted message is sent to the retailer who doubly encrypts the initially received encrypted message from P under his own unique encryption key (K.sub.R) and this doubly encrypted message is sent to the bank. The person also sends the transaction message to the retailer in clear, and the retailer first verifies the message and then, utilizing his own encryption key (K.sub.R), encrypts same and similarly sends it to the bank.