一个新的两重门限代理签密方案

New double-threshold proxy signcryption scheme from bilinear pairings

在签密理论中引入两重门限技术,构造一个新的基于双线性对的两重门限代理签密方案。在该方案中,把第一重(k,n)门限体制应用在密钥共享上,原始签密人把密钥委托给n个秘书来托管,至少k个秘书合作才能恢复此密钥,大大降低了密钥泄露的风险;将第二重(t,m)门限体制应用在代理签密过程中,把签密权委托给m个代签人共享,任何少于t个代理签密者勾结也不能得出正确的签密密文,在很大程度上增强了代理签密的安全性。理论分析表明,说明该方案是可证明安全的,适合实际应用。

By applying the concepts of double threshold technology to signcryption theory, a new double-threshold proxy signcryption scheme from bilinear pairings is proposed.In this new scheme, the first （k, n）threshold technology is adopted in the key sharing,the original signcrypter entrusts this key to n secretaries for escrow,at least k secretaries cooperate can recover the key.It greatly reduces the risk of key-compromise.The （t, m） threshold technology is adopted in the process of proxy signcryption,it gives the right of signcryption to entrust m proxy signcrypters sharing, no less than t proxy signcrypters with no right can receive the correct cipher text.To a great extent, it enhances the security.Analysis shows that the scheme is secure, and it is suitable for many applications in practice.