<scp>IoT</scp>‐Enabled Blockchain Framework for Internet of Vehicles Safety Monitoring in Smart Cities

ABSTRACT Road accidents pose a significant concern, leading to numerous fatalities and societal disruptions. The Internet of Vehicles (IoVs), when integrated with communication technology, offers a promising solution to mitigate these accidents. However, current IoV systems face challenges such as data integrity, user privacy, centralized storage, and secure authentication. Blockchain technology emerges as a viable solution, providing tamper‐proof data storage and a trustless authentication independent of central authorities. However, in blockchain‐based IoV systems, the inefficiency of traditional consensus mechanisms suffers from high computational costs, network delays, and limited scalability. To address these challenges, we introduce HybridChain, an IoT‐enabled blockchain framework that uses the Reputation‐Based Practical Byzantine Fault Tolerance (RB‐PBFT) consensus mechanism, which enhances transaction throughput, reduces consensus delay, and mitigates block congestion by incorporating a reputation‐based trust model. RB‐PBFT ensures that only trusted entities participate in block validation. Furthermore, HybridChain integrates a sidechain‐based storage mechanism to manage the large volume of data, ensuring that only essential metadata is recorded on the main blockchain, thereby enhancing scalability and reducing network congestion. The experiment results show that the amount of data transmitted is 4.3 times more in PoW than RB‐PBFT with varying vehicles, while in the case of varying block size, it is 3.1 times more in PoW than RB‐PBFT.