# A Proof-of-Multiple-State Consensus Mechanism for Mobile Nodes in Internet of Vehicles
## 2 Related Work  
In recent years, there has been an increasing integration of blockchain into the Internet of Vehicles (IoV), with the aim of considering complex vehicle scenarios and improving the provision of blockchain services in the IoV. This has led researchers to propose new consensus algorithms [7; 8; 9]. Currently, blockchain-based IoV models [10] are on the rise, leveraging decentralization, immutability, and transparency to transform traditional centralized IoV architectures. This widespread application offers significant development prospects for the IoV. Currently, significant research efforts are aimed at refining the blockchain's consensus mechanism to eliminate inefficiencies and resource waste of traditional consensus methods. Various consensus algorithms are developed that are tailored to different scenarios [11; 12] and improve communication efficiency over classic consensus mechanisms. Existing consensus mechanisms mostly refine and improve classic schemes such as Proof-of-Work (PoW) [13] and Byzantine Fault Tolerance (PBFT) [14]. The PoW algorithm requires users to perform time-consuming and complex calculations, which incurs significant costs in terms of time, equipment, and energy. The PBFT algorithm resolves node breakdown in asynchronous environments caused by malicious attacks and software errors. Current algorithms achieve a fault tolerance of \((\mathrm{n}-1)/3\), ensuring liveliness and security. In [15], an improved DPoS algorithm is proposed that provides higher throughput and a two-layer blockchain structure for improved consensus efficiency and scalability. Inaddition, there are also many similar approaches to [16], which combine multiple traditional consensus mechanisms to create new consensus mechanisms. However, these classic improvement schemes tied to the static node environment have problems in systems with frequently changing node communication quality. In [17], a novel lightweight PoBT (Proof of Block and Transaction) algorithm and integration framework for the IoT blockchain is proposed, which can verify transactions and blocks with reduced computation time. Literature [18] introduces Proof of Credit (PoC), a blockchain protocol that focuses on fairness and includes a self-verification and hybrid incentive mechanism that is resistant to double-spend and self-serving mining attacks. However, the protocol oversimplifies the Proof-of-Work process to effectively select the leader nodes. Ref. [19] minimizes consensus size and network overhead by dividing nodes into communication groups and assigning node roles based on trust factors, thereby optimizing communication resources. An efficient consensus algorithm is proposed in paper [20] to reduce the communication overhead, where the leader dynamically adjusts the reputation values of nodes according to their behavior and allows high-performing nodes to transmit data efficiently. This approach significantly improves the responsiveness of the blockchain, especially in large node environments. While these consensus mechanisms optimize the dynamic attributes of the network, they primarily address the communication overhead between nodes without considering the continuous mobility of nodes. The EPoW consensus introduced in [21] shortens the waiting time for arithmetic mining by executing the algorithm regularly. It also improves consensus efficiency by managing a specific set of miners and assigning multiple accounting rights. These methods prioritize changing reputation scores and aim to limit malicious nodes within the network. However, they do not sufficiently consider the communication process between nodes. The environments assumed by existing consensus algorithms are predominantly static and immutable. Therefore, this paper focuses on the specific requirements of IoV scenarios, especially with regard to mobile node communication.