Blockchain-based cryptocurrencies has received a substantial interest in the last decade as Blockchain can ensure trust among users without relying on third parties. However, cryptocurrency adoption for micro-payments has been limited due to slow confirmation of transactions and unforeseeable high fees, especially in the case of Bitcoin. To this end, creating off-chain payment channels between users is proposed which enables instant and nearly free transactions without writing to blockchain. Off-chain channel idea is then extended to establish payment channel networks to scale the idea to allow payment routing among many users. However, due to the way these channels are designed, both sides of a channel have a fixed one-way capacity for making transactions. Consequently, if one side consumes the whole one-way capacity, the channel becomes non-transitive in that particular direction, which causes failures of payments that would like to pass through. Eventually, the network becomes partitioned with unevenly distributed funds. In this paper, we propose the adoption of three specific techniques that aim to increase the overall success rate of payments and address channel imbalance problem to keep the payment channel network sustainable in the long run. First, we show the effectiveness of balance-aware routing that better utilizes available funds in the channels. Second, we propose an efficient method for selection of the gateway (i.e., connection point) for a user by considering the gateway’s inbound and outbound capacity. It exploits the fact that end-users can connect the network through multiple gateways any of which can be used to initiate the payment. Finally, we propose proportional payment splitting method to further increase success rate especially for large transactions. We implemented the three approaches for assessing their effectiveness. Compared to existing approaches such as maximum flow or greedy, the proposed approaches can achieve much higher success rates with channels balanced better.

在过去的十年中，基于区块链的加密货币引起了人们的极大兴趣，因为区块链可以确保用户之间的信任而无需依赖第三方。然而，由于交易确认速度缓慢和不可预见的高额费用，小额支付采用加密货币受到了限制，特别是在比特币的情况下。为此，提出了在用户之间创建脱链支付渠道的建议，这种方式可以实现即时和几乎免费的交易，而无需写入区块链。然后扩展脱链渠道构想以建立支付渠道网络，以扩展构想以允许许多用户之间进行支付路由。但是，由于这些通道的设计方式，通道的两侧具有固定的单向交易能力。因此，如果一侧消耗了整个单向容量，渠道在该特定方向上将变为不可传递，从而导致希望通过的付款失败。最终，网络变得分散，资金分布不均。在本文中，我们建议采用三种特定的技术，旨在提高支付的整体成功率并解决渠道不平衡问题，以长期保持支付渠道网络的可持续性。首先，我们展示了平衡感知路由的有效性，该路由可以更好地利用渠道中的可用资金。其次，通过考虑网关的入站和出站容量，我们提出了一种有效的方法来为用户选择网关（即连接点）。它利用了一个事实，即最终用户可以通过多个网关连接网络，任何网关都可以用来发起付款。最后，我们提出按比例付款拆分方法，以进一步提高成功率，特别是对于大型交易。我们实施了三种方法来评估其有效性。与诸如最大流量或贪婪之类的现有方法相比，所提出的方法可以实现更高的成功率，并且可以更好地平衡渠道。