Abstract: In accordance with one embodiment, a chip is provided which includes an interface configured to receive test data and masking data, a processing component having a plurality of scan chains. Each scan chain is configured to generate a test response on the basis of a processing of the test data. The chip further includes a compression circuit configured to compress the test responses generated by the scan chains to form a compressed test response, and a signature generating circuit configured to generate a signature on the basis of the compressed test response, depending on whether the masking data specify that the compressed test response is to be masked.