Hierarchic arrangement for the verification and renewal of security data in electronic fund transfer systems.

摘要

A pay or credit card (A) is inductively coupled to a data transfer programming and processing and display unit (B) which in turn is coupled via inductive coupling links (2b-2c, 3b-3c) to a third unit (C) which comprises mostly miniaturized circuitry such as more particularly storage registers (31) for two <<wrong>> security check numbers and four <<right>> such numbers and auxiliary logic circuitry, as also a transaction list memory (63). The latter may be constituted as a fully sealed tape unit with built-in stepping motor and solid-state comparator circuitry. The said security check numbers are received and from time to time updated via inductive coupling links (2d-2e, 3d-3e) from a main transaction office (D) such as a bank, credit card office, etc, and during a card transaction, responsive to a reference number emitted by the card, selects one or more of the <<right>> numbers and a <<wrong>> number. The automatic sequence changer circuit (32) presents to the card an unpredictable sequence of the selected numbers and then tests the card reaction to this input, in a response evaluator circuit (33). The test and transaction list unit (C) would be optional at a card terminal and required only at off-line stations (f.e. for smaller traders and vending machines where separate data lines to banks would not be economical).Where on-line operation is possible, the bank computer (D) would perform the check operations of unit C. Accordingly, the bank computer (D) would communicate during day time with cards (A) via processors (B) which belong to on-line terminals, while during night time and early morning hours the accummulated off-line transactions are received from test and transaction storage unit (C) via a modem (D min ), when also the cyclically required modification of one of the registers (31) is performed. The Bank Computer (D) itself receives from time to time modification instructions for its security check number register via interbank data lines from Bank Head Office. The Head Offices of different banks receive similar data from a single random data generator or clearing bank director respectively. A card processor for unpredictable sequence of right and wrong test numbers has first been described in British patent application 79 31 208, and is here presented as a complete card data and regional transaction transfer security system.