属性基门限签名方案及其安全性研究

 属性基门限签名方案要求用户的身份用一系列的属性来描述,签名者的权力由其所拥有的属性集合决定.验证者通过验证该签名,只能确定该签名者属性集与验签属性集合相同的属性数目超过门限值个,具有保护属性隐私的作用.本文分析了Li等人的灵活门限签名方案,发现其存在签名伪造的安全问题.针对该方案安全性方面的不足,本文设计了一个安全可证的属性基门限签名方案,并基于CDH困难假设,在标准模型下证明了该签名算法的安全性.

Threshold Attribute-Based Signature and Its Security

A threshold attribute-based signature (t-ABS) scheme defines each signer with a set of attributes,which determine signature ability for each signer.In a t-ABS,signature holder prove possession of signatures by revealing only a threshold number of attributes in common with the verification attribute set,hence providing signer-attribute privacy for the signers.In this paper,we analyze a flexiblethreshold ABS proposed by Li et al and demonstrate its vulnerability to forgeable attacks.Finally,we introduce a t-ABS scheme,which is proved to be secure in the standard model based on CDH problem.