Differential Power Analysis for Cryptographic ICs

Based on the concrete circuit of embedded system which was realized by AT89C52 microchips and encrypted with DES, the paper introduces the design and implementation of differential power analysis (DPA) attack which is one of the typical and powerful ways of side channel attacks (SCA). This paper explains the relations among the power consumption characters and data-dependent power consumption of CMOS logic gates which function the integrated circuits (ICs). With 10⁵ plaintexts and power consumption samples, 48-bit key of the round 16 of DES was detected successfully. Then the rest 8 in 56-bit effective key of DES was detected easily by exhaustive attack. The result indicates that DES encrypted systems without special protective measures are not strong enough to survive from the attacks of DPA, because of the leakage of the emission of physical signals and the difference of power consumption while processing the different data in ICs.