一种改进的针对滑动窗口模幂运算实现的密码数据Cache计时攻击  

Improved Data-Cache Timing Attack on Cryptography Adopting Sliding Window Method for Modular Exponentiation

作　　者：周平[1] 寇应展[1] 王韬[1] 赵新杰[1] 刘会英[1] 

机构地区：[1]军械工程学院计算机工程系,石家庄050003

出　　处：《计算机科学》2013年第3期201-205,共5页Computer Science

基　　金：国家自然科学基金(61272491;60772082)资助

摘　　要：RSA、DSA等公钥密码大都基于"滑动窗口"算法实现模幂运算,其运算过程中进行的Cache访问会产生旁路信息泄漏并用于密钥破解,基于Cache访问泄漏的幂指数分析算法是提高攻击效率的关键。通过分析现有攻击的不足,进一步分析了预计算乘法因子到Cache的映射规律,提出了一种基于窗口值判定的幂指数分析改进算法;以基本模幂运算为例,通过实际攻击实验验证改进算法的效率,结果表明改进算法可恢复出60%的幂指数位,优于前人最好工作的47%;最后以RSA和DSA为例,给出了改进算法对密钥分析的影响。Public-key cryptography, such as RSA and DSA, adopt sliding window method for modular exponentiation, from which side-channel information can be leaked while accessing Cache during execution, thus private key can be de- crypted. Exponent analysis algorithm is the key point to improve the efficiency of the attack. By analyzing the shortco- ming of previous work, this paper farther analyzed the relationship between Cache-access trace and precomputed multi- pliers and proposed an improved exponent analysis algorithm based on window-value identifying. Experiments were made to prove the efficiency the improved algorithm and results showed that the improved algorithm was able to recover 60% exponential bits,which is better than the previous result 47%. In the end, the application of the improved algo- rithm was showed on RSA and DSA.

关 键 词：滑动窗口 模幂运算 RSA DSA CACHE计时攻击 

分 类 号：TP393.08[自动化与计算机技术—计算机应用技术]