Fraud protection for card transactions

Abstract

The problems of fraud in card transactions can be reduced by, after requiring the person engaged in the card transaction to initially identify himself, such as by supplying a card number, a) requesting, the person to supply as authentication information either 1) a randomly selected piece of prestored information or 2) information derived from a randomly selected piece of prestored information; and b) completing the transaction only if the authentication information requested is correctly supplied. The authentication information requested is described in terms of its nature, i.e., what it represents, so that one can not deduce from the request the correct response without knowing the selected prestored piece of information. Since the authentication information is randomly determined for each card transaction, a thief will rarely, if ever, be able to successfully complete a card transaction simply by supplying, in response to a request, the same piece of authentication information last supplied by the authorized person. Each authorized person already knows the particular pieces of information that are prestored for him, e.g., birthdate of spouse, year of school graduation, and mother's telephone number. Thus, he need exert no extra effort to remember them. If the pieces of prestored authentication information are various numbers they may be transmitted over a telephone network from a caller to the authorization system using currently available dial pads and DTMF signaling.