BRAV: Blockchain-Enabled Revocable Authentication for UAV-Assisted Internet of Vehicles

Unmanned aerial vehicle (UAV)-assisted Internet of Vehicles (IoV) improves the robustness of vehicle-to-Road Side Unit (RSU) connectivity in settings with sparse roadside infrastructure and severe urban blockage. However, introducing airborne relays and open wireless links also substantially enlarges the attack surface. Existing authentication schemes for this scenario typically provide only session-level anonymity, while revocation is either omitted or delegated to a single trusted authority, making the system vulnerable to well-known attacks and yielding revocation views that are neither scalable nor consistent across RSUs. To address these issues, we propose BRAV (Blockchain-enabled Revocable Authentication for UAV-assisted Internet of Vehicles). BRAV enhances self-updating hash chains to enable cross-session pseudonym evolution with public-transcript unlinkability against external observers. Moreover, BRAV introduces a Dual Cuckoo Filter revocation mechanism that leverages the globally confirmed state of a consortium blockchain to support fast, compact, and verifiable revocation queries, while maintaining a consistent revocation view among RSUs. We prove session-key security of BRAV in the Real-or-Random model and validate its authentication and secrecy properties using Scyther. Experimental results show that BRAV maintains practical computation and communication overhead while providing stronger security coverage than lightweight baselines. Its filter-based revocation significantly improves query efficiency over conventional certificate revocation lists (CRLs) and a single-filter baseline, and reduces storage consumption by about 87% compared to CRLs. Finally, NS-3 and blockchain simulations further demonstrate the applicability of BRAV in UAV-assisted IoV deployments.