Patent ID: 7539588

Claim:
A data carrier comprising a circuit, which circuit comprises the following components: a first memory device, which is designed for modifiable storage of information, the information being modifiable by an ambient parameter of the circuit, which ambient parameter acts on the first memory device, characterized in that the first memory device comprises a test memory area, which is provided for storing test information, wherein the first memory device comprises multiple data sectors and wherein the test memory area comprises data sector-specific test memory areas within each of the multiple data sectors, wherein the test information is stored within the data sector-specific test memory areas and wherein the data sector-specific test memory areas are located in an area of each data sector that is designated for access control, and a second memory device is provided which is designed for unmodifiable storage of reference information, and detection means are provided, to which the test information which may be read out from the first memory device and the reference information which may be read out from the second memory device may be supplied, and said detection means are designed, with the aid of the read-out test information and the read-out reference information, for detecting a modification of the originally stored test information brought about by an ambient parameter acting on the first memory device.