首先分析了Liu等人2013年给出的一个格基身份签名(IBS)方案在安全性证明中存在的问题,进而说明方案的证明达不到作者所宣称的选择身份和自适应选择消息攻击下的强不可伪造性。其次,使用Boyen10签名技术(PKC2010)对此方案中签名算法进行改进,并在标准模型下证明了改进方案在选择身份和自适应选择消息攻击下具有强不可伪造性的安全性质。另外,对比分析了改进的方案和其他IBS方案的效率和安全性。
Liu et al proposed an identity-based signature from lattices in 2013, and proved that it can achieve strong un- forgeability in the standard model. Through analysis, the security proof of this scheme has some defect, and then show that the scheme cannot prove the strong unforgeability under selective identity and adaptive chosen-message attacks. Then, using Boyen signing technique (PKC 2010) inpoves the signing algorithm, and proves the strong unforgeability under selective identity and adaptive chosen-message attacks (SU-slD-CMA) in the standard model. In addition, it com- pares the efficiency and security of the scheme and the other identity-based signatures from lattices.