Harn数字签名方案的改进

Harn数字签名方案中 ,签名者不需计算任何逆 ,验证者只需计算 2个模指数 ,因此相对于其它基于离散对数数字签名方案计算量大大减少。但该方案 ,不能抵抗同态攻击 ,并且随机密钥 k不能重复使用。文章针对该方案的不足 ,提出一种改进方案 ,新方案不但保留了 Harn数字签名计算速度快及容易实现密钥共享等优点 ,而且能够有效抵抗同态攻击 ,并且在随机密钥 k重复使用时能够确保方案的安全性

Improvement of Harn digital signature scheme

In the Harn digital signature scheme,the signatory need not compute any inverses and the person who verifies the key only need compute two modular exponents, so the computation work is less in comparison with other schemes based on discrete logarithm. But in using the Harn scheme,the homomorphism attack can not be resisted and the random key k can not be used reduplicatively. Aiming at this drawback, an improved scheme is introduced,in which not only the advantages of the Harn scheme are kept,but also the homomorphism attack is resisted effectively. In addition, the new scheme can ensure the scheme's security when the same random key k is used.