Patent ID: 6219651
Filing Date: 2001-04-17
Classification: G06Q,G07F

Abstract:
A procedure for protecting transaction data in cash-free payment traffic by means of a chip card in a payment terminal, the procedure comprising:a) inserting an electronic purse chip card in a read and/or write device;b) initiating a transaction for payment of a certain amount using said electronic purse chip card;c) creating corresponding transaction data for a payment procedure, for each said payment procedure;d) creating corresponding cumulative data for each said payment procedure, where the cumulative data includes transaction data since a last data exchange with a settlement position, ande) creating a cumulative signature on each supplement to said cumulative data, where said new cumulative signature is formed from the initial value of the previous cumulative signature;f) resetting the cumulative data in a security module after a data exchange, with the settlement position and an initial value for the creation of the cumulative signature being established.