VDKMS: Vehicular Decentralized Key Management System for Cellular Vehicular-to-Everything Networks, A Blockchain-Based Approach

The rapid development of intelligent transportation systems and connected vehicles has highlighted the need for secure and efficient key management systems (KMS). In this paper, we introduce VDKMS (Vehicular Decentralized Key Management System), a novel Decentralized Key Management System designed specifically as an infrastructure for Cellular Vehicular-to-Everything (V2X) networks, utilizing a blockchain-based approach. The proposed VDKMS addresses the challenges of secure communication, privacy preservation, and efficient key management in V2X scenarios. It integrates blockchain technology, Self-Sovereign Identity (SSI) principles, and Decentralized Identifiers (DIDs) to enable secure and trustworthy V2X applications among vehicles, infrastructures, and networks. We first provide a comprehensive overview of the system architecture, components, protocols, and workflows, covering aspects such as provisioning, registration, verification, and authorization. We then present a detailed performance evaluation, discussing the security properties and compatibility of the proposed solution, as well as a security analysis. Finally, we present potential applications in the vehicular ecosystem that can leverage the advantages of our approach.

I. Introduction

With the rapid growth of connected and autonomous vehi-cles, vehicular networks are becoming increasingly important, and Key Management Systems (KMS) play a critical role in ensuring the security and integrity of these networks. Public Key Infrastructure (PKI) is a widely adopted KMS that provides secure communication, authentication, and data encryption among vehicles. However, despite its significance, the current implementation of PKI in vehicular networks faces several issues that undermine its effectiveness. The primary challenges faced by PKI in vehicular networks include: (1) Compatibility issues-The limitations of Vehicular Ad hoc Networks (VANETs) create compatibility challenges, such as supporting computer-network based communication protocols that are essential for secure data exchange among vehicles. (2) Single points of failure-The centralized nature of PKI introduces risk for faults, however small, that can compromise the entire system's security and stability if it is attacked or simply malfunctions. (3) Complex verification process-The trust model in PKI leads to an intricate verification method, which can be inefficient and resource-intensive, especially for time-sensitive vehicular communication. (4) Privacy preser-vation-Ensuring the correctness of the verification process while also hiding sensitive privacy information is a major concern. Achieving a balance between privacy preservation and secure communication is vital for maintaining user trust and the overall functionality of vehicular networks. Given these challenges, it is essential to explore alternative solutions, such as Decentralized Key Management Systems (DKMS), which can address these issues and provide a more secure, ef-ficient, and resilient framework for vehicular communication. However, implementing DKMS in existing VANETs and their communication systems presents its own set of limitations and complications that need to be addressed in order to fully har-ness the potential of decentralized vehicular networks. Thus, we propose a novel Vehicular Decentralized Key Management System (VDKMS) for Cellular Vehicular-to-Everything (V2X) networks, which leverages the advancements in Self-Sovereign Identity (SSI) and Decentralized Identifier (DID) to create a secure, scalable, and efficient key management schema, specif-ically tailored to overcome the limitations of implementing DKMS in existing VANETs and their communication systems.