A New Conditional Privacy-Preserving Certificateless Aggregate Signature Scheme in the Standard Model for VANETs

Abstract

Vehicular Ad Hoc Networks (VANETs) take moving vehicles and transport facilities as nodes to form mobile networks through wireless communication technology. Its application increases traffic safety and promotes the development of intelligent transport. However, VANETs have security concerns in data transmission. Fortunately, aggregate signature schemes can enhance security and efficiency in the VANETs. Nevertheless, some aggregated signature schemes for VANETs still have security concerns. In this paper, we conduct a security analysis of a conditional privacy-preserving CLAS scheme for VANETs proposed recently. The analysis reveals that the scheme exhibits vulnerabilities to the KGC attack and public key replacement attack. We propose an improved scheme to fix security vulnerabilities in response to these issues. Subsequently, formal and informal security assessments are conducted for the improved scheme, demonstrating that it fulfills security requisites. Furthermore, performance assessment demonstrates the practical viability of the refined scheme.