EPA-Route: Routing Payment Channel Network with High Success Rate and Low Payment Fees

Existing blockchain systems suffer from low throughput and high payment latency. Payment channel networks (PCNs) such as the Lightning Network are proposed as a viable scaling solution. In PCNs, two participants can establish a payment channel to transfer funds without manipulating the blockchain. However, PCNs must route transactions between not directly connected participants on paths with sufficient funds. Since link capacities in PCNs vary as transactions are performed, it is hard to apply classical techniques to route PCN transactions directly. In this paper, we propose EPA-Route, a routing algorithm that aims to achieve both a high success rate and low transaction fees for PCNs. In addition, EPA-Route still maintains high performance and decentralization characteristics. In EPA-Route, every participant maintains a routing table. For every transaction, EPA-Route first probes possible paths based on the routing table and prunes useless paths at every hop to alleviate overheads. After a collection of paths obtained after probing and pruning, EPA-Route splits the transaction into several sub-transactions and allocates them to these paths. The allocation is formulated as an optimization problem to minimize transaction fees. Extensive experiments show that EPA-Route reduces up to 85 % transaction fees and maintains a comparable success rate as state-of-the-art algorithms.