Establishing Trustworthy and Privacy-Preserving SAGIVNs in 6G: Architectures, Requirements, and Solutions.

Vehicular networks have huge potential to enhance road safety, improve traffic efficiency, reduce energy consumption, and decrease pollution emission. However, only relying on ground segment is unable to provide satisfactory wireless communication services for vehicles at any time and any where. The emergence of the 6th Generation (6G) fully achieves Space-Air-Ground Integrated Vehicular Networks (SAGIVNs), which is a paradigm of the Space-Air-Ground Integrated Network (SAGIN) architecture applied into vehicular networks. Nevertheless, due to the huge, open, heterogeneous, and highly dynamic characteristics, the SAGIVNs are vulnerable to several kinds of trustworthiness and privacy threats which greatly limit their performance. In this article, we propose a novel privacy-preserving trustworthiness evaluation solution in SAGIVNs, to achieve a satisfactory balance between trustworthiness and privacy preservation. Meanwhile, the proposed solution can simultaneously provide rapid decision, reputation feedback mechanism, traceability mechanism, and Sybil attack resistance ability. Furthermore, we conduct a comprehensive performance evaluation and comparison, and the results demonstrate that the proposed solution is significantly superior to the existing state-of-the-art solutions in several aspects.