The original payment channel paper described a two-party payment channel, where trust was ensured by each party watching the blockchain for the other's settlement request. This works well, but does not scale; for an N-party channel, one requires all N parties to be in consent with each other before a channel is considered settled and anyone can get their funds out. A hub-and-spoke architecture for a payment channel aims to address that, but now the hub has a few new problems: it has to keep track of all its smart contracts, it has to stake its own funds to each and every one of them, and it has to periodically rebalance those smart contracts to ensure the continued operation of those channels. This once again limits how fast and how far a payment channel can scale. There have been multiple creative ideas proposed to help with these new problems, including creating a payment channel mesh network, but so far none of these ideas have been able to address them sufficiently to produce a mainstream system based on a payment channel that can scale up and down freely.