TA-Offline Integrated Cross-Domain Authentication for Low-Altitude IoV

Abstract

Low-altitude networking and embodied intelligence are driving the Internet of Vehicles (IoV) toward a vehicle-roadcloud-air collaborative architecture, where vehicles frequently interact with both ground Roadside Units (RSUs) and Unmanned Aerial Vehicle (UAV)-assisted RSUs. In this setting, single access authentication cannot satisfy practical requirements, because the target domain must verify migration permission and then sustain lightweight trust for subsequent interactions. Existing schemes mainly emphasize conventional V2I access, standalone cross-domain authentication, or heavy trust infrastructures, and few of them jointly consider target-domain authorization, UAV assistance, and post-migration continuous authentication. To address this issue, we propose CD-BPCH, a lightweight crossdomain continuous authentication scheme enhanced by bivariate polynomial (BP) and chameleon hash (CH) for low-altitude IoV. In CD-BPCH, the trusted authority (TA) establishes an epoch-level chameleon-hash authorization anchor for each target RSU/UAV-RSU, while an authorized vehicle generates a hiddenopening collision proof bound to the target identifier, dynamic pseudonym, locally derived key, and timestamp. This design allows the target RSU/UAV-RSU to verify migration authorization locally without learning the trapdoor or maintaining vehiclespecific chameleon-hash values. In addition, a symmetric bivariate polynomial enables the vehicle and the target RSU/UAV-RSU to derive a shared authentication key without repeated TA participation. After migration authentication, lightweight hash tokens are used to support multi-round continuous authentication. Security analysis shows that CD-BPCH provides mutual authentication, anonymity, traceability, replay resistance, impersonation resistance, and local verification against semitrusted RSUs. Performance evaluation further indicates that CD-BPCH achieves low cumulative computation and communication overhead, which makes it suitable for low-altitude embodied IoV scenarios.