Service-oriented vehicular ad hoc networks (VANETs) are expected to support the diverse infrastructure-based commercial services, including Internet access, real-time traffic concerns, video streaming, and content distribution. The success of service-oriented VANETs depends on the underlying communication system to enable the user devices to connect to a large number of communicating peers and even to the Internet. This poses many new research challenges, particularly on the aspects of security and user's privacy. In this paper, we propose a novel privacy-preserving data-forwarding scheme based on our proposed novel Lite-CA-based public key cryptography and on-path onion encryption technique. The proposed scheme is expected to not only thwart the traffic tracing attack at the minimized computational overhead but to provide an efficient way to relieve workload and deployment complexity of certificates as well. Performance comparisons and security analysis show that the proposed schemes are very efficient and suitable for service-oriented VANETs.