Trust management in VANETs is critically important for secure communication between vehicles. In event-based trust systems, vehicles broadcast the events they witness to their surroundings and send feedback reports about other vehicles to a central authority. However, when the event status changes, vehicles that have left the witness area cannot see this change and produce erroneous feedback. This leads to unfair penalization of honest nodes. To solve this problem, the SAFE (Spatially-Aware Feedback Enhancement) approach is proposed. In SAFE, vehicles continue to record messages as long as they remain in the witness area and send updated feedback reports before leaving the area. Additionally, by keeping records between witness and decision distances, more accurate evaluation is ensured. SAFE and TCEMD were compared in single-event, multi-event, and different decision distance scenarios. The results clearly demonstrate SAFE's superiority. In single-event, feedback report count increased 2.5 times, and in multi-event, it increased over 6 times. Negative feedback rate dropped from 77 percent to below 1 percent. While TCEMD incorrectly blacklisted 34 nodes, this number remained at 1 in SAFE. Even when the decision distance was reduced to 200 m, SAFE showed high accuracy. The findings show that SAFE protects honest nodes in attack-free systems and increases network reliability.

翻译：车载自组织网络中的信任管理对车辆间的安全通信至关重要。在基于事件的信任系统中，车辆向周围环境广播其目击事件，并向中央权威机构发送关于其他车辆的反馈报告。然而，当事件状态发生变化时，已离开目击区域的车辆无法察觉到这种变化，从而产生错误反馈，导致诚实节点受到不公平惩罚。为解决此问题，本文提出了SAFE（空间感知反馈增强）方法。在SAFE中，只要车辆仍处于目击区域，就会持续记录消息，并在离开该区域前发送更新的反馈报告。此外，通过在目击距离与决策距离之间保存记录，可确保更准确的评估。我们在单事件、多事件及不同决策距离场景下比较了SAFE与TCEMD。结果清晰地证明了SAFE的优越性。在单事件场景中，反馈报告数量增加了2.5倍；在多事件场景中，反馈报告数量增加了6倍以上。负面反馈率从77%降至1%以下。TCEMD错误地将34个节点列入黑名单，而SAFE中该数字仅为1。即使决策距离缩短至200米，SAFE仍表现出高准确性。研究结果表明，SAFE在无攻击系统下保护了诚实节点，并增强了网络可靠性。