| 摘要 |
The invention relates to a method for the secure transfer of data (D0-D4) whose coding (`S`,`0`-`F`) is represented by a sequence (FR0-FR4) of a predefinable number of on and off values (Z1,Z0), whereupon a count value (C) representing the predefinable number is formed, the direction of counting (F,R) is altered after each on value and the count value is incremented or decremented, and error information (F1,F2) is produced if a first end value (EC), which is transferred with the data as a coded sequence (SIG) of the count value C, is different from a second end value (EC1,EC2) which is formed like the count value from the transferred sequence. The method can be used advantageously in identification systems (IS), mobile data carriers (DT) and write/read devices (SLG). One advantage of the invention is that a data transfer error can be recognized both quickly and with a high degree of certainty by using a simple up and down counter (CNT). The counter can be embodied in the form of a simple software program or an electronic circuit, i.e. a cyclic counter, requiring only a small amount of circuit technology for the manufacture thereof. |
