一种防欺诈的安全增强型广义门限签密方案

A Security Enhanced Generalized Threshold Signcryption Scheme with Deceit Detection

分析了Wang等人提出的广义门限签密方案(WCL方案)及其改进方案(TJC方案等)的安全缺陷,指出这些方案无法抵抗等式攻击等多种安全攻击,不能实现门限解签密,也不能检测恶意成员的欺诈行为。针对这些问题,提出一个防欺诈的安全增强型广义门限签密方案。新方案通过引入随机分量的方法将秘密参数R设计为可变参量,能够有效抵抗已知文献提出的各种攻击,具备真正意义上的(t,n)门限签密和(k,l)门限解签密的广义门限特性;此外,通过引入非交互式离散对数等式知识证明协议,新方案还能够检测出恶意成员的欺诈行为。最后,效率评测表明新方案在大多数情况下比WCL方案更高效。

By analyzing the first generalized threshold signcryption scheme （ WCL scheme） and its improved schemes （ TJC scheme,etc. ） ,it was found that they can’t resist several attacks such as equation attack and can’ t realize threshold designcryption. In order to remedy their security flaws,a novel security enhanced generalized threshold signcryption scheme was presented. In the new scheme,the random factor was added to the secret parameter R so as to completely realize the function of generalized threshold signcryption,i. e. （ t,n） threshold signcryption and （ k,l） threshold designcryption,and by means of Chaum-Pedersen discrete logarithm equation knowledge protocol,malicious members’deceitful behaviors could also be detected. Security analysis and efficiency evaluation showed that this new scheme could resist all the attacks proposed in previous literatures and was more efficient than WCL scheme with respect to computation and communication costs.