Bitcoin's Lightning Network Moves Closer to Compatibility

Nearly a year after bitcoin's scattered group of Lightning Network developers first gathered to unite their different implementations, the rules they could one day use to connect their technologies are almost complete.

In interviews, those involved with the open-source project (viewed as one of the best ways to bring additional capacity to the nearly $70 billion network), spoke to the new sense of direction provided by bitcoin's recent SegWit upgrade. Still, they also cautioned that, while SegWit lays the foundation for Lightning, standards are needed to connect work that's already been done.

"The specification is mostly complete, with minor amendments and inconsistencies that we are figuring out," said Blockstream engineer Christian Decker, co-author of an early Lightning research paper at ETH Zurich.

Put another way, if each Lightning implementation used different technologies, then the networks wouldn't be able to "talk" with one another, and thus wouldn't be useful for sending payments across the network. (Alice would not be able to send to a payment to Bob if he were using another, incompatible network.)

Lightning engineers, however, are almost done drawing up the standards. Lightning Labs CEO and co-founder Elizabeth Stark told CoinDesk:

"The specification isn't 100% at 1.0 yet, but it's very close."

Building BOLTS

While this marks a major step for the second-layer payment network, however, there are plenty of other steps still to take.

The open-source GitHub specifications, comprised of 11 Lightning "BOLTs," now describe the technical details that all implementations need to work on, such as transaction formats and how messages should be passed across the network.

The most obvious next step is translating these BOLT rules into actual code, though work here is also well underway. (MIT Digital Currency Initiative and bitcoin startups ACINQ, Blockstream and Lightning Labs are all currently coding up implementations that obey these rules.)

Additionally, Decker said he is working on a tool that tests how well the Lightning implementations work together. As Lightning developers finish coding up what's in the specifications, this will allow them to test whether they're truly compatible.

However, while it's "moving along nicely," Decker said the tool, just like the other parts of the Lightning Network, is still in progress.

Disclosure: CoinDesk is a subsidiary of Digital Currency Group, which has an ownership stake in Blockstream and Lightning Labs.

Lightning strike image via Shutterstock