提出了利用保密增强后处理的方法来实现基于互耦合激光器混沌同步的安全密钥分发。采用基于随机码的通用类哈希函数对不安全的裸钥进行保密增强处理,可产生安全的密钥。数值模拟表明,经保密增强处理后,合法通信方密钥与窃听者的密钥间的互相关系数下降了1个数量级;合法通信方的信息泄露量最高仅为10-5比特量级;窃听者对安全密钥比特的平均正确窃听概率接近于零信息泄露量概率值0.5。该方法可有效解决窃听者通过单向耦合同步方式的窃听问题,增强混沌密钥分发系统的安全性。
A secure key distribution scheme based on mutually coupled chaos synchronization is achieved by utilizing privacy amplification To generate security keys,privacy amplification utilizing universal hash functions based on random bits is proposed to distill highly secure shared information. Numerical results indicate that after privacy amplification, correlation values of legitimate user’s and the attacker’s keys are reduced by an order of magnitude; maximum information leakage is as low as the order of 10-5 ; the attacker's success probability of bit guessing is close to 0. 5 (zero information point). The results above indicate that the information leakage caused by the attacker' s eavesdropping by unidirectionally coupling to synchronize with the legitimate could be eliminated, and the security of key distribution based on chaos synchronization could be enhanced.