A Proof-of-Transactions Blockchain Consensus Protocol for Large-Scale IoT

Blockchain technology can benefit Internet of Things (IoT) in terms of message exchange, access control, and management; however, existing blockchain consensus protocols cannot provide sufficient performance without compromising security and fairness. This article proposes a round-based two-stage blockchain consensus protocol called Proof-of-Transactions (PoT) for a variety of requirements, such as performance and security of large-scale IoT. In the first stage of each round, all nodes preconstruct new blocks and exchange information about the number of valid transactions contained in each other's blocks. The block containing most valid transactions is broadcasted in the second stage and examined by all nodes of the cluster before being received as the new block in the global blockchain ledger. The consensus reaching of a new block requires only two rounds of message exchange process. Theoretical analysis and experimental results verify the feasibility and superiority of the proposed protocol.