Investigations Of Power Analysis Attacks And Its Countermeasures On SMS4 Cipher Algorithm

Power analysis attacks is a brandnewtechnology of cipher analysis that breaks thetraditional attacks model, it has drawn broad attention among users due to its highattacking efficiency and low cost. There are many papers referring to how to accomplishthe power analysis attacks of DES, AES etc. SMS4, as the first commercial algorithmreleased by Chinese government, has been playing a significant role in the area of theinformation security and cryptography. However, there is no published report about thepower analysis attacks and defense of SMS4.Therefore, this thesis takes power analysis attack and defense of SMS4 as researchtarget, it has completed the following contents:1. Analyzed the structure and characteristics of SMS4 algorithm indepth,putforward three of the implementation of power analysis attack starting points, as well asthe methods of attacks. The feasibility and correctness of these three attacks have beenvalidated through simulation based on the Hamming weight of the power leak model.2. On the basis of research on power analysis attacks of SMS4 algorithm, thecharacteristics of the data which has been processed in the three attack points have beenanalyzed. This thesis accomplishes the defense of power analysis attacks by processingthe intermediates and improving the key expansion algorithm. In this thesis, threeadvanced methods have been proposed and their defensive ability of power analysisattacks has been verified by simulation experiments.