Patent ID: 6892937
Filing Date: 2005-05-17
Classification: G06Q,G07F,H03K

Abstract:
1. A method for operating a multistage counter in only one counting direction, which comprises the steps of: changing a counting value of a single-stage auxiliary counter, which counts in only one counting direction, in dependence on predetermined target values of the multistage counter; registering counting values of the multistage counter and of the single-stage counter; logically linking the counting value of the single-stage auxiliary counter with supplementary data to form first authenticity data; transmitting the first authenticity data together with said counting value of the multistage counter, to a checking device; recovering the counting value of the single-stage auxiliary counter in the checking device resulting in a recovered counting value; generating second authenticity data by logically linking the recovered counting value of the single-stage auxiliary counter with the supplementary data; and comparing the first authenticity data with the second authenticity data.