Method and circuit configuration for debiting a debit card
AssigneeSiemens Aktiengesellschaft
InventorHartmut Schrenk
Life of this patent
Estimating the term…
Abstract
A debit card carries an integrable electronic circuit which is electronically debited. The circuit includes a nonvolatile, electrically erasable and writable memory operated as a multi-stage counter with counter stages. The circuit is provided with a nonvolatile, electrically erasable and writable check memory which has check memory regions associated with respective counter stages of the counter memory. The card is debited in that at least one of the memory cells of a memory is read out with at least two different weighting thresholds, and the counter memory is controlled as a function of the results obtained in that reading. The reading of the carry bit and the associated check bit allow to safely prevent against manipulation and the circuit may be realized at a very low expense.
Claims9
A method for debiting an integrable electronic circuit of a debit card, wherein the electronic circuit comprises a nonvolatile, electrically erasable and writable counter memory operated as a multi-stage counter with counter stages, and wherein the electronic circuit further comprises a nonvolatile, electrically erasable and writable check memory having check memory regions associated with respective counter stages of the counter memory, the method which comprises:
- defining at least two different weighting thresholds,
- reading at least one memory cell of each of the counter memory and the check memory with the at least two different weighting thresholds, and controlling a counting process in the counter memory as a function of results obtained in the reading step.
Dependencies are inferred from the claim text.