一个基于双线性映射的前向安全门限签名方案

将前向安全的概念引入到基于双线性映射的门限签名方案中,提出了一个基于双线性映射的前向安全的门限签名方案.该方案将签名密钥分散到签名成员集合中,采用各成员部分密钥前向更新的方式实现了签名密钥的前向更新,增强了签名密钥的安全性,使得签名方案具有前向安全性.另外,由于部分密钥具有前向更新的特性,从而方案有效防止了移动攻击.对该方案的安全性进行了分析,分析表明,该方案是安全、有效的.

identity based threshold proxy signature

IEEE Computer Society

Competitions of magnetism and superconductivity in FeAs-based materials

Using the numerical unrestricted Hartree-Fock approach, we study the ground state of a two-orbital model describing newly discovered FeAs-based superconductors. We observe the competition of a (0, π) mode spin-density wave and the superconductivity as the doping concentration changes. There might be a small region in the electron-doping side where the magnetism and superconductivity coexist. The superconducting pairing is found to be spin singlet,orbital even, and coexisting sxy + dx~2-y~2 wave (even parity).