A novel security framework based on blockchain for IoT networks

Internet of Things (IoT) devices are indispensable components of smart cities, smart homes, and industrial control systems. Using a blockchain (BC)-based security framework in IoT security is extremely necessary and a current research trend. However, most current BC-based decentralized security frameworks have not yet reached the optimal performance of miners in transactions verification and data consensus in the BC ledger. In this paper, we present a novel BC-based security framework for ensuring the correctness and reliability of the data in the BC ledger and optimizing miners’ performance over an IoT network. We propose the process of verifying transactions and data consensus based on two assumptions about miners in a BC network: (1) all miners are trusted nodes, and (2) some miners are untrusted nodes but less than one-third of the total number of miners. The evaluation results show that the more miners join the network, the more verified transactions increase and the lower the average mining time for a new block for assumption 1. For assumption 2, transactions only need to be verified once even if an untrusted miner is selected to propose a new block at a mining round. The proposed framework is more effective than other decentralized frameworks in the process of verifying transactions and data consensus.