无随机预言模型的(t,k,l)-门限代理签名方案

(t,k,l)-Threshold Proxy Signature Without Random Oracle

推广了（t,l）-门限代理签名概念,提出了（t,k,l）-门限代理签名.在一个（t,k,l）-门限代理签名中,由指定的l个代理签名者构成的群体必须要求有至少k个人的合作才能生成代理签名,同时方案中最多允许参与的t-1个人合谋.给出了第1个门限代理签名方案存在性不可伪造的安全性模型,提出了一个基于CDH问题的（t＋1,2t＋1,l）-门限代理签名方案,并且在无随机预言机的模型下证明了该方案是存在性不可伪造的,同时还具有可区分性和代理保护等性质.

To generalize the concept of（t,l）-threshold proxy signature scheme,this paper proposed a（t,k,l）-threshold proxy signature scheme,in which any k or more proxy signers in a designated proxy group of l members can cooperatively issue a proxy signature and this scheme can also tolerate at most t-1 corrupted signers.The security model of existential unforgeability for the threshold proxy signature scheme was presented,then a（t ＋1,2t ＋1,l）-threshold proxy signature scheme based on the hardness of CDH problem was proposed,and the existential unforgeability was proved under this security model.At the same time,this scheme has the properties of distinguishability and proxy protected.