MPC: Multi-node Payment Channel for Off-chain Transactions

Abstract

Payment channel (PC) greatly improves blockchain scalability by allowing an unlimited number of off-chain transactions instead of committing every transaction to the blockchain. However, one PC just confines to two nodes. Thus, for a node, like Cafe, who frequently receives money from multiple nodes, massive PCs need to be created, which leads to massively and repeatedly information addition of channels to the blockchain and costs much fees. In this paper, we introduce a multi-node payment channel (MPC) method to solve the problem above. MPC suits the scenario that one node frequently receives money from multiple nodes, such as Cafe, shop, etc. Compared to PC, MPC can contain nearly unlimited number of nodes, thus avoiding repetitive channel information addition to the blockchain and meanwhile reducing the fee. MPC supports the same transaction logic of PC and cooperates well with existing PC. The security, economy and efficiency of MPC are proved. We implement MPC’s smart contract in Ethereum and experimental results show that MPC outperforms the existing PC.