Research On Differential Power Analysis Attack On Two Kinds Of Stream Ciphers

With the rapid development and universal application of cryptography, the methods of cryptanalysis present characteristics of increasingly diversification. Side channel analysis attack is a kind of attack, which appears at mid 1990s of last century. It's different from the classical cryptanalysis techniques which adopt mathematical theories of algebra and probability. It achieves the goal of obtaining secret information by measuring physical characteristics of cryptographic devices. The appearance of side channel analysis attack breaks the traditional idea about information security, and the physical security of cryptographic algorithms and their hardware products receive much more concern. Differential power analysis attack (DPA attack) is one of the research hotspot among side channel analysis attacks. Since the beginning of NESSIE and ECRYPT stream cipher project, the research on DPA attacks on stream ciphers have been paid enough attention to. Seeking the methods of DPA attack on stream ciphers, especially according to those feedback shift register (FSR) based and the ones chosen by eSTREAM, has important significance. It can obtain the secret information, improve the security of stream ciphers when they were in practical applications, and promote cryptanalysts to design much more secure stream ciphers.By analyzing the stream cipher algorithms'characteristics, hardware implementations and power consumption, two DPA attacks of FSR-based stream ciphers are presented.Single clock power consumption based DPA attackNeighboring clocks'power consumption based DPA attack Then the thesis presents two DPA attacks on the stream cipher MICKEY:Hamming distance of shift registers sorting based DPA attackFeedback value based DPA attack And then we check the soundness and efficiency of them by theoretical prove and simulation attack.The main research contents are composed of two sections:The first section studys DPA attacks of FSR-based stream ciphers. We analysis the key exhaustive space of single clock power consumption based DPA attack on DECIM, then generalize it to general condition, namely FSR based stream ciphers. This kind of DPA attack only uses single clock power consumption of FSR. By investigating the relationship between neighboring clocks'power consumption of FSR, and on the basis of DPA simulative attack which is based on DECIM's single clock power consumption, we make improvement on it, then give out neighboring clocks'power consumption based DPA attack. It can reduce the algorithm noise's influence to the attack. So it enhances the precision of selection function, reduces the key exhaustive space of DECIM from O(2~80) to O(2~32).The second section studys two DPA attacks of the stream cipher MICKEY. We make use of the characteristic of the known states among parts of flip flops in the initialization phase of MICKEY, and then build the relationship between power consumption and the Hamming distance of shift register's flip flops which the states are unknown, and give out Hamming distance of shift registers sorting based DPA attack. By analyzing the structure of hardware implementation of MICKEY, we find that three-input-xor unit can be seen as the basic hardware unit of MICKEY. By analyzing the power consumption distribution of register R and S in different conditions, and discussing the buildup of power consumption of MICKEY in several kinds of circumstance, the connection of feedback value and power consumption has been discovered. Hereby we give out feedback value based DPA attack. The simulation experiment results show: For the MICKEY which is standard implemented, it is vulnerable to the two DPA attacks.