Last Week in Bitcoin (Jan 12 - 18)

Highlights from the bitcoin developer ecosystem...

Hi Insiders. This is Tuma, open-source reporter from the Insider Edition. I spent 10+ hours in open-source developer calls in the Bitcoin ecosystem last week. Here is what caught my eye:

• PR177 in sv2-apps is removing a workaround from bitcoin_core_sv2 , following a fix in the new Bitcoin Core v30.2 release.

  • During the weekly call, on Tuesday 13th, Stratum V2 developers discussed PR177, which leverages the latest Bitcoin Core v30.2 to remove a temporary workaround for working with the new IPC mining interface.

  • The workaround was introduced to address IS33575 in Bitcoin Core, which highlighted that the IPC mining interface did not provide a way to cancel the waitNext call. The goal of this function is to wait for certain events (e.g. a new tip) to occur to provide a new BlockTemplate to the caller.

  • However, waitNext has to be initialized with the correct constraints for the coinbase outputs, so that the previous loop could be stopped and relaunched. Thus, Bitcoin Core developers introduced a new method called interruptWait() in PR33676, providing the needed API.

  • Since the workaround has been removed, the next versions of the bitcoin_core_sv2 crate will only be compatible with versions of Bitcoin Core ≥ v30.2.

• PR1190 in CDK has been merged and is improving the efficiency of payment requests.

  • During the weekly call, on Wednesday 14th, CDK developers announced that PR1190 had been merged, following the official inclusion of NUT-26 in the Cashu protocol specifications.

  • The new specification and related PR introduce an alternative encoding format for payment requests based on bech32m encoding and TLV (Tag-Length-Value) serialization, aligning the Cashu protocol to the standard applied to Bitcoin addresses and Lightning invoices.

  • The new alternative offers many advantages with respect to the original one. In fact, it provides higher compatibility with QR codes, more than 30% reduction in size, better error handling, and improved human readability.

• PR1236 and PR1289 in BOLTs are nearly ready. These PRs are the last step missing before proceeding with the final merge of the splicing specification.

  • During the monthly specifications call, on Monday 12th, Lightning Network developers discussed the status of PR1236 and PR1289. These PRs need to be merged before pushing the splicing specification and they are waiting for a final ACK from the CLN team.

  • PR1236 updates BOLT2, the peer protocol for channel management, allowing both channel parties to send tx_init_rbf in v2 channel establishment. This change is being implemented for consistency with splicing, since its specification already allows for both the initiator and the accepter to initiate the RBF process.

  • PR1289 also updates BOLT2. This change makes it mandatory for nodes to retransmit signatures in case peers disconnect in the middle of the signing step of an interactive transaction. In particular, the PR introduces an explicit bitfield that lets a node request the commitment_signed message if they have not received it.

Looking for an opportunity to join up with some bitcoin devs in person? Join us in Florianopolis this February 26-28 to talk about exploiting Bitcoin.