SAFE: Spatially-Aware Feedback Enhancement for Fault-Tolerant Trust Management in VANETs

TL;DR

SAFE enhances trust management in VANETs by maintaining spatially-aware feedback, significantly reducing false penalties and improving network reliability through continuous message recording within witness areas.

Contribution

The paper introduces SAFE, a novel spatially-aware feedback method that improves trust evaluation accuracy in VANETs by addressing event status changes and spatial considerations.

Findings

Feedback report count increased 2.5 times in single-event scenarios.

Negative feedback rate decreased from 77% to below 1%.

SAFE reduced incorrect blacklisting from 34 to 1 node.

Abstract

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.