Overview on Security Approaches in Intelligent Transportation Systems
This is an incremental survey paper that addresses the problem of comparing security architectures for researchers and practitioners in intelligent transportation systems.
The paper surveys security issues and solutions in Vehicular Ad-hoc Networks (VANETs) for Intelligent Transportation Systems, categorizing them into centralized, decentralized, and hybrid trust architectures, and finds that hybrid approaches are underrepresented in current research.
Major standardization bodies developed and designed systems that should be used in vehicular ad-hoc networks. The Institute of Electrical and Electronics Engineers (IEEE) in America designed the wireless access in vehicular environments (WAVE) system. The European Telecommunications Standards Institute (ETSI) did come up with the "ITS-G5" system. Those Vehicular Ad-hoc Networks (VANETs) are the basis for Intelligent Transportation Systems (ITSs). They aim to efficiently communicate and provide benefits to people, ranging from improved safety to convenience. But different design and architectural choices lead to different network properties, especially security properties that are fundamentally depending on the networks architecture. To be able to compare different security architectures, different proposed approaches need to be discussed. One problem in current research is the missing focus on different approaches for trust establishment in VANETs. Therefore, this paper surveys different security issues and solutions in VANETs and we furthermore categorize these solutions into three basic trust defining architectures: centralized, decentralized and hybrid. These categories represent how trust is build in a system, i.e., in a centralized, decentralized way or even by combining both opposing approaches to a hybrid solution, which aims to inherit the benefits of both worlds. This survey defines those categories and finds that hybrid approaches are underrepresented in current research efforts.