一种群签名方案的分析及改进

Analysis and Improvement of a Group Signature Scheme

提出一种改进的基于中国剩余定理的群签名方案:有人申请加入群时,加强申请人与群中心传递参数的验证,确保信息没有被篡改,无法冒充成员加入群;群成员的签名中不含有该人信息,保证成员签名之间无关联性;群成员撤销时,对成员公钥修改进行限制,确保撤销成员无法继续签名.解决了Wang方案群成员私钥泄露、签名关联性、被撤销成员伪造签名和非法成员加入等问题.分析表明,所提方案对群中心与群成员之间传递的信息严格验证,能够满足群签名方案的安全需求.

Based on Chinese remainder theorem, an improved signature scheme is proposed to strictly verify the validity of the parameters transferring between the applicant and group center when a person is applying for joining the group, prevent the information from interpolation and ensure that no impostor can join the group. Then the information on a candidate even impostor is impossible to be included in the signatures, thus providing the irrelevance among all signatures. When deleting a group member, the scheme will restrict the modifications to be made to the public key of the member so as to ensure that no way will the member sign. The proposed scheme solves the problem as shown in Wang＇ s scheme, such as divulging private key, signature relevance, forgery attack of revoked member and invalid join. Analyzed results showed that the proposed scheme can meet the security for the group signature.