公开验证和前向安全数字签密方案的分析与改进

Attack analysis and improvement on the signcryption scheme with public verifiability and forward security

指出张建航等提出的数字签密方案无前向安全性,提出了一个新的可公开验证和前向安全的数字签密方案,并进行了正确性和安全性分析,与已有方案比较,降低了算法复杂度.同时,指出张建航等提出的椭圆曲线数字签密方案复杂度过高,给出了一个新的签密方案,方案具有前向安全性和公开验证性,模乘运算达到最小值4次,模逆运算达到最小值0次,复杂度达到理论最小值.

The signcryption scheme proposed by Zhang Jian-hang et al is analyzed, and the scheme don＇t have the forward security. An improvement scheme is proposed with public verifiability and forward security, the correctness and security are proved. The efficiency of the scheme is increased significantly compared with two existing schemes. Moreover, a new signcryption scheme based on elliptic curves is proposed with public verifiability and forward security. In the algorithm, both the numbers of model multiplication and model inverse are reached the minimum four times and zero times, the efficiency of the algorithm is increased significantly compared with the existing signcryption scheme.