With the increasing complexity of vehicular network environments, conventional authentication mechanisms often struggle to simultaneously achieve robust privacy preservation and operational efficiency. To overcome these limitations, this study proposes a novel lightweight authentication framework that integrates blockchain technology, zero-knowledge proofs (ZKPs), and smart contract mechanisms. The proposed scheme facilitates secure mutual authentication between vehicles and roadside units (RSUs) while maintaining the confidentiality of credentials, thereby achieving unlinkability and resistance to common security threats. Our design incorporates a three-tier verification process within smart contracts, encompassing: credential existence validation through blockchain records, ZKP-based identity verification, and message integrity assurance via message authentication codes (MACs). Extensive performance evaluations demonstrate the scheme’s practical viability, with experimental results showing significantly reduced registration and authentication latency compared to existing solutions, while maintaining rigorous security standards.