Overcoming Dynamic Connectivity in Internet of Vehicles: A DAG Lattice Blockchain with Reputation-Based Incentive

Blockchain offers a promising solution to the security challenges faced by the Internet of Vehicles (IoV). However, due to the dynamic connectivity of IoV, blockchain based on a single-chain structure or Directed Acyclic Graph (DAG) structure often suffer from performance limitations. The DAG lattice structure is a novel blockchain model in which each node maintains its own account chain, and only the node itself is allowed to update it. This feature makes the DAG lattice structure particularly suitable for addressing the challenges in dynamically connected IoV environment. In this paper, we propose a blockchain architecture based on the DAG lattice structure, specifically designed for dynamically connected IoV. In the proposed system, nodes must obtain authorization from a trusted authority before joining, forming a permissioned blockchain. Each node is assigned an individual account chain, allowing vehicles with limited storage capacity to participate in the blockchain by storing transactions only from nearby vehicles’ account chains. Every transmitted message is treated as a transaction and added to the blockchain, enabling more efficient data transmission in a dynamic network environment. A reputation-based incentive mechanism is introduced to encourage nodes to behave normally. Experimental results demonstrate that the proposed architecture achieves better performance compared with traditional single-chain and DAG-based approaches in terms of average transmission delay and storage cost.