Research And Implementation Of Countermeasures Against Side Channel Attacks For Public Key

As the fast development of information technology, network informationsecurity has been given widely concern and attention. Therefore, people usewidely public key algorithm which can implement many cipher technology tosupport information security. For additional security and efficient, public keyalgorithm is often implemented in embedded device. However, this can bevery vulnerable to side channel attacks. Side-channel attacks mean that theattacker can obtain the secret data through the side-channel informationwhich generated in the computation of cryptographic algorithm. Generally,side-channel information includes executing time, power consumption,electromagntic radiation and fault result. The corresponding attack is timinganalysis attack、power analysis attack、electromagnetic analysis attack andfault injection analysis attack(FIA). And power analysis includes simplepower analysis (SPA) and differential power analysis (DPA). The analysismethod of electromagnetic analysis is the same as power analysis. Thedifference is the signal acquisition.This paper researchs the basic theory of sidd-channel attacks(includepower analysis attack、electromagnetic analysis attack and fault injectionanalysis attack), and introduces the side-channel attacks and countermeasuresof public key algorithm such as RSA and ECC. Considering the feature ofRSA and ECC algorithm, we research some countermeasures with highsecurity and performance to resist side-channel attacks. In order to furtherimprove performance, we study on the hardware implement of RSA and ECC,especially the basic unit modular multiplier. Then combine the software toimplement the countermeasures agaist side-channel attacks. Finally, we build corresponding attack platform to verify our proposed countermeasure. Duringthe researching process, we obtain the main results as follows:1. Study on the MIST modular exponentiation algorithm using randomaddition chains, which is very vulnerable to simple power analysisattacks. Then we propose a secure and efficient MIST modularexponentiation, which additionally employs dummy operations foragainst SPA and modidies the choice of divider for efficiencies. Thismethod also be used to scalar multiplication.2. FIA for modulus n is analized. According to this attack feature, wepresent a new MIST modular exponentiation algorithm to resist it,which adds the integrity check of n and calculates the last step twotimes, then compares the two results.3. Research countermeasures of ECC against power analysis attacks,most of which sacrifice efficiencies. Combined with the windowtechnique, a secure and effective multi-scalar multiplication algorithmbased on the NAF representation is proposed to resist SPA. And ascalar multiplication can be changed to multi-scalar multiplicationthrough splitting the scalar using a random number. Then this scalarmultiplication also can resist DPA, and don’t sacrifice efficiencies.4. Study on the implement of countermeasures. Based on the optimizedMontgomery algorithm and two32bit multipliers, an effectivearchitecture for modular multiplication is designed. Then RSA andECC algorithm are implemented in hardware. And combined withsoftware, the technology of preventing side-channel attack can be alsoimplemented. Finally, we construct attack platform to verify ourproposed countermeasures.