Access protected data carrier with semiconductor chip, has operation which is modified prior to its execution, and is supplied with modified input data

摘要

The data carrier (1) comprises a semiconductor chip (5) with at least one memory, in which an operating program is stored. This executes at least one operation requiring input data, and produces output data. The operation is modified prior to its execution, and is supplied with modified input data. The modification of the operation and the input data is performed in such way, that output data are produced, which are identical with the output data produced for execution the unmodified operation with unmodified input data.