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 6th Generation (6G) is expected to fully achieve 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 first analyze the architectures and limitations of traditional vehicular networks, and illustrate the general architecture of SAGIVNs. Besides, we analyze the conflicting requirements of trustworthiness and privacy preservation in SAGIVNs, and review three state-of-the-art solutions which aim at resolving the conflict between trustworthiness and privacy preservation in SAGIVNs. Moreover, we propose a new solution which can simultaneously provide rapid decision, reputation feedback mechanism, traceability mechanism, and Sybil attack resistance ability. In addition, we conduct comprehensive performance evaluation and comparison, and the results demonstrate that the proposed solution is superior to the existing solutions on the whole.