A Security Analysis and Optimization of ECC-Based Aggregate Signature Algorithms
Vijaya Lode, Kiran Gedela, Anil Pinapati · 2025
Vehicular ad hoc networks (VANETs) are pivotal in advancing transportation efficiency and safety by enabling uninterrupted communication among vehicles and network devices. They are crucial elements of intelligent transportation systems (ITS) by facilitating real-time traffic updates, collision warnings, and congestion management. However, their dynamic and open nature exposes them to significant security challenges, such as disinformation propagation and malicious attacks. To mitigate these risks, a certificateless aggregate signature (CLAS) was proposed and demonstrated that it is not forgeable. However, our analysis uncovered a significant vulnerability: the scheme fails to ensure non-repudiation, fails to detect signature swapping and message injection attacks, and the RSU mistakenly validates the aggregate signature even though an invalid signature is present. This weakness undermines the validity of aggregate signatures and compromises the integrity of the system. In this paper, we conduct an in-depth cryptanalysis of the original CLAS scheme and propose modifications to address its vulnerabilities and ensure privacy. The proposed design strengthens the resistance of the scheme to these weaknesses. Through comprehensive security and performance evaluations, we demonstrate that the modified CLAS scheme mitigates these security issues; it significantly improves privacy and security without sacrificing computational efficiency.