Local Pooling of Connected Supernodes in Lightning Networks for Blockchains

Abstract

The lightning network (LN) is a special network in Bitcoin that uses offchain micropayment channels to scale the blockchain's capability to perform instant transactions without a global block confirmation process. However, micropayment scalability in a large LN and liquidation for small nodes still remain major challenges for the LN. In this paper, we introduce the notion of supernodes and the corresponding supernodes-based pooling to address these challenges. In order to meet the high adaptivity and low maintenance cost in the dynamic LN where users join and leave, supernodes are constructed locally without any global information or label propagation. Each supernode, together with a subset of (non-supernodes) neighbors, forms a supernode-based pool. These pools constitute a partition of the LN. Additionally, supernodes are self-connected. Micro-payment scalability is supported through node set reduction as only supernodes are involved in searching and in payment with other supernodes. Liquidation is enhanced through pooling to redistribute funds within a pool to external channels of its supernode. Extensive simulations have been conducted to validate the improvement in routing scalability and liquidation of the proposed architecture under different settings.