增强JavaCard中Schnorr签名的预处理方案

摘要

The security performance of the Schnorr signature protocol for JavaCard was analyzed in order to enhance security and improve the efficiency. A linear cryptanalysis scheme based on key-recovery attack against the signature protocol was presented, and the feasibility of the attacking method was proved by a case of successful attack. On this basis, a notion of security preprocessing was proposed, which is a linear detection based scheme. The linear detection random numbers and corresponding variables were stored in the special areas of JavaCard. This approach can avoid generation of random number and the complexity modular exponentiation when the digital signature is created in card. Security performance analysis result shows that the proposed scheme not only can promote the operation speed effectively with the same hardware platform and cryptography intensity,but also avoids a type of linear cryptanalysis.%为增强JavaCard的安全与执行效率,研究用于JavaCard中签名与认证的Schnorr算法,基于密钥恢复攻击技术,提出一种针对Schnorr签名的线性攻击方法,通过实例测试了该攻击的可行性.在此基础上,设计一种安全预处理方案,该方案使用一个线性检测器对随机数进行线性检测,将经过线性检测的随机数组和相应变量存入卡中特殊区域,避免了签名时在卡内产生随机数,且签名过程不用在卡内进行大运算量的幂模运算.实验结果分析表明:该方案可以大幅度提高处理速度,改善签名效率,同时避免了一类安全攻击.