Abstract: The trust management systems in Vehicular Ad-hoc Networks（VANETs） require users to disclose their reputation-related information, which will bring dangers to user privacy. To deal with the collusion between trust and privacy, a novel “pseudonym-reputation” collaborative change scheme is presented in this paper. This scheme is based on the k-anonymity theory and user-centric strategy. The personalized privacy protection is considered and a PK-PCS strategy is presented. Experiments show that the PK-PCS strategy is better than the traditional Pseudonym Change Strategy（PCS） strategy and K-anonymity Pseudonym Change Strategy（K-PCS） strategy in privacy preservation, satisfaction and data loss. The PK-PCS not only maintains the usefulness of trust, but also protects the privacy of users.

Key words: Vehicular Ad-hoc Network（VANET）, trust management, reputation, privacy preservation, pseudonym

摘要： 车载自组网中的信任管理系统要求用户的声誉相关信息充分公开，这会给用户隐私带来隐患。为解决信任与隐私的冲突问题，提出“假名-声誉值”协同变换策略。新策略以k匿名隐私保护理论和用户中心策略为基础，同时考虑了用户个性化隐私保护需求，提出了PK-PCS策略。仿真实验表明PK-PCS策略在车辆隐私保护、满意度、数据损失方面整体优于现有PCS策略和K-PCS策略。PK-PCS既保持了信任的有用性，又同时保护了用户隐私。

关键词: 车载自组网, 信任管理, 声誉, 隐私保护, 假名