An Efficient Multimode Certificateless Ring Signcryption Scheme in VANETs

The swift advancement of new energy vehicles and the integration of autonomous driving technologies have propelled vehicular ad hoc networks (VANETs) into a prominent research focus. Numerous privacy protection schemes have been proposed to ensure secure and anonymous communication within VANETs. Nevertheless, the prevailing privacy protection schemes can only accommodate a single level of anonymity, posing challenges in meeting the requirements of intricate application scenarios. In many conditional traceable ring signcryption schemes, malicious users can render traceability ineffective through the simple alteration of relevant tracking parameters. To confront these challenges, we introduce an efficient multimode certificateless ring signcryption scheme. Our scheme seamlessly combines full anonymity, linkable anonymity, and revocable anonymity within an unified algorithm, offering variable degrees of anonymity to accommodate diverse communication scenarios. In the conditional traceable mode, any attempt by malicious users to manipulate tracking parameters results in the rejection of the message. Moreover, we have rigorously demonstrated in the random oracle model (ROM) that our scheme upholds confidentiality and unforgeability. Our comprehensive performance and simulation analyses reveal that, in comparison to several existing similar schemes, our approach significantly diminishes computational costs by a minimum of 45.61%. Moreover, it achieves notable success in reducing communication costs, showcasing a minimum reduction of 52.61%, and boasts the lowest transmission delay.