A Scalable State Channel for IoT Using Interactive Consistency Protocols

Scalability remains a fundamental challenge when using blockchains for building Internet of Things (IoT) applications. The throughput of blockchains is not suitable to process the high volume of data produced by IoT devices and public blockchain fees can be prohibitive when IoT devices generate lots of data. This paper proposes a novel state channel that is suitable for building IoT applications. This facilitates the processing of numerous transactions outside the main blockchain. Similarly to any other layer-2 scaling solution, the state channel is designed to decrease direct interactions with the main blockchain by processing and computing tasks off-chain. This reduces fees while increasing the throughput. Unlike existing state channels, the proposed IoT state channel does not require monitoring or synchronising with the main blockchain. In addition, very few data are exchanged between the processes composing the state channel and the main blockchain. Our IoT state channel makes use of a solution to the well-known interactive consistency problem and requires the majority of off-chain processes to act correctly. This ensures that correct processes reach the same sequence of states throughout the entire state channel lifetime. An evaluation of two state channel implementations using two distinct interactive consistency protocols is provided.