Research On DPA Attack Of Smart Care Based O DES With Back-Forth Random Round

With the rapid development of chip technology, smart cards in the military, finance, government, and other fields have been widely used, at the same time, crime rate for password cracking is becoming more and more high. The current smart card password cracking method can be divided into two types:the mathematical crack based on password system and the crack with side channel information, the latter is represented by side channel analysis (SCA) attack. Power analysis (PA) attack is one of the main means of SCA, which use the correlation between leakage power consumption and processing data in the implementation process of cryptographic algorithms to recover the key related information. Among PA attack methods, differential power analysis (DPA) attack has become an important method for smart cards password attack, due to its strong attack ability, and unrelated to the specific encryption algorithm based on smart card. The new defense measures for PA attack mainly has two kinds:mask and random round. Compared with mask, the implementation of random round is simple, less cost, thus it becomes main defense measures of smart cards. Random round is divided into two kinds according to round position: back-forth random round and middle random round.Based on the study of DPA attack and defense for smart cards, accumulative attack algorithm and segmented attack algorithm, aiming at back-forth random round, are proposed for the first time according to different attack nodes. Smart card encryption keys are recovered through a large number of experimental data, which proves back-forth random round can’t resist DPA attack. This paper mainly do the following work:(1) Combine hardware and software to realize DPA attack for general smart cards. According to the power data correlation model, use MATLAB simulation to realize DPA attack on general smart cards on the basis of the principle of DES algorithm and DPA attack, and then establishe hardware platform for verification;(2) Set up two kinds of DPA attack model for back-forth random round, and put forward accumulative attack algorithm and segmented attack algorithm. Acoording to characteristics of back-forth random round, averaging or segmented attacking the front (DR+1) power curves respectively to restore keys, that is accumulative attack algorithm and segmented attack algorithm, and verify them by MATLAB simulation; Optimize the judging way of keys according to the calculation results of segmented attack algorithm, and improve the algorithm, finally, summarize the advantages, disadvantages and the applicable scope of the two algorithms;(3) Designe and realize DPA attack system for DES algorithm. According to characteristics of general smart cards and smart cards with random round, using MATLAB and JAVA WEB technology, without hardware supporting, realize DPA attack on power consumption waveforms of smart cards with DES algorithm. This system concisely presented results at various stage of the attack, which make users clearly understand the principle of DPA attack without complex programming, so it’s suitable for basic teaching and research.