Abstract: In order to provide a data processing device (100), in particular an embedded system, such as a smart card, comprising at least one integrated circuit (102) carrying out calculations, in particular cryptographic operations, as well as a method for operating such data processing device (100) wherein costs are minimised, the requirements on the complexity of the design are decreased, the power consumption is reduced and the performance of a cryptographic operation is enhanced, it is proposed to protect the integrated circuit (102) against cryptanalysis, in particular against differential power analysis, by hiding the power consumption profiles of said calculations and by alternating between different power consumption profiles, in particular by introducing one or more counter signals (51; 61; 71, 81), for example one or more signals of at least roughly opposite amplitude relative to an average amplitude, wherein the sum of the respective amplitude of the one or more original or true signals (50; 60; 70, 80) may