Abstract: Real-time sharing in IoVs imposes stringent demands for high trust,high privacy,and high concurrency,whereas exis-ting blockchains struggle to simultaneously address storage overhead,off-chain tampering,and robustness under dynamic topologies.To this end,this paper proposes ChainGrid-V,a highly scalable framework built upon three core technologies:decentralized dual-Merkle verification that leverages a local-global tree structure to reduce consistency-check complexity to O(log n+log k),sustaining an 80% detection rate under 30% shard tampering for single nodes and 65% under multi-node collusion with repair latency ≤8.5 s;RAW hybrid consensus that fuses Proof-of-Authority for leader election,Proof-of-Reputation for weighted voting,and lightweight Proof-of-Work as a fallback,augmented by a dual-decay exponential reputation-recovery function enabling millisecond-level weight reclamation for dishonest nodes and seamless replacement by trusted ones,maintaining >500 TPS in a 70-node network and achieving 93.5% consensus success even with 30% Byzantine nodes,with system recovery in only 1.6 s;a lightweight privacy stack where on-board units locally generate zero-knowledge proofs whose on-chain verification latency is below 10 ms,enabling raw-data privacy protection and integrity verification without trusted hardware.Joint simulations with 200 OBUs,50 RSUs,and 30 storage nodes show that ChainGrid-V's throughput and latency differ by <7% from Raft-PoA and DAG-IoV,while its security margin improves by 15%~20%,fully satisfying automotive-grade high-frequency low-latency requirements and demonstrating large-scale deployment potential.

Key words: IoV, Blockchain storage, Dynamic consensus mechanism, Zero-knowledge proof, Tamper-resistant verification, Reputation model