改进的基于格的动态群签名方案

An Improved Dynamic Group Signature Scheme Based on Lattice

为了提高基于格的群签名的效率和实用性,本文基于小整数解问题(SIS)和错误学习问题(LWE),提出了一个新的基于格的群签名方案.该方案只需要更新一小部分群公钥和群成员私钥就可以有效地加入和撤销群成员,适用于群成员数较多和成员更新比较频繁的群签名,由群成员生成签名私钥,能够抵抗陷害攻击,在随机模型下,具有CPA-匿名性和CCA-追踪性,并且其群签名长度不再依赖于群成员的数量.与现有的方案相比,该方案有效地实现了群成员的加入和撤销,并且减小了签名的长度,更加实用.

In order to improve the efficiency and practicability of the group signature,a new group signature scheme was proposed,and its security of CPA-anonymous and CCA-traceable was proved based on the hardness of the LWE（learning with errors）or SIS（short integer solution）problems in the random oracle model.The group members can be added or revoked efficiently by only updating a fraction of group public keys and group member keys.The signature secret key is generated by the group members so that this scheme is anti-trap attacks.Compared with other group schemes over lattice,this scheme can increase and revoke group members more efficiently and can resist track attack,and the size of the signature does not rely on the number of group members any more.This scheme is appropriate for the group signature with more members or the frequent members updating.