An Improved CP-ABE Scheme With Black-Box Traceability Based on Logical Location for Cloud-Based VANETs

The rapid evolution of the Internet of Things (IoT) and vehicular ad-hoc networks (VANETs) has underscored the urgent need for robust data access control mechanisms. ciphertext-policy attribute-based encryption (CP-ABE) emerges as a promising solution by leveraging users’ inherent attributes to define access privileges, thus providing a secure and flexible approach to access control. Despite the flexibility of ciphertext-policy ABE (CP-ABE), its deployment in VANETs faces several challenges, including limited edge resources, heavy reliance on a centralized trusted authority that may hinder scalability and introduce single points of failure, and inefficiency in addressing key misuse and identity forgery, all of which significantly impact system performance and scalability. In response to these challenges, we propose an efficient decentralized cloud-based CP-ABE system that integrates active and robust black-box traitor tracing, wherein each user is bound to unique and implicit logical location. These bindings enable precise tracing and accountability, which allows the scheme to efficiently identify the traitor through multiple interactions and prevent collusion between entities. The distributed scheme offers strong traitor tracing capabilities, ensures IND-chosen-plaintext attack (CPA) security, and maintains low-computational overhead, thereby making it well-suited for resource-constrained edge devices in VANETs. Finally, extensive deployment experiments on edge devices and formal security proofs are provided to demonstrate the scheme’s performance.