Common Knowledge Base Association (CKBA) (@ckba_build): The blockchain beneath a payment channel network does more than settle disputes. It defines what the network can become.

The blockchain beneath a payment channel network does more than settle disputes. It defines what the network can become. Lightning inherits Bitcoin’s security and decentralization, but also its constraints. A Lightning channel can ultimately enforce only the rules Bitcoin understands, using Bitcoin Script and Bitcoin’s single native asset. Consider Eltoo, now commonly called LN-Symmetry. It’s a upgrade that would allow the newest channel state to override any earlier one, replacing Lightning’s penalty-based revocation model with a simpler update mechanism. But Bitcoin cannot support it today. The design requires new consensus functionality, such as ANYPREVOUT or an alternative, meaning it remains dependent on a future Bitcoin soft fork. Now, Fiber takes the same basic payment channel model but builds on top of CKB. On CKB, channel settlement rules are programs executed by CKB’s RISC-V VM. This means Fiber is not confined to one fixed channel design. Developers can introduce new ways to fund, update, authorize, settle, and resolve channels by deploying new scripts. It also gives Fiber a much broader design space than Lightning. Channels can support multiple assets, atomic swaps, programmable payment conditions, and more flexible dispute mechanisms. In other words, Fiber takes the very narrow payment channel model that Lightning pioneered and turns into a programmable financial primitive. The result is a more expressive network: one that can evolve faster, support more kinds of value exchange, and serve use cases that Lightning’s underlying architecture was never designed to accommodate.