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:

• An update on the latest NUT changes: Keysets ID V2, bech32m encoding, and more.

  • During the monthly community call, on Thursday 29th, Cashu developers announced several updates to the NUT specifications. Some changes have already been merged, while others are still work-in-progress, waiting for protocol implementations to develop the new features.

  • Several PRs were merged to update specifications. Notably, PR182 updates NUT-02, providing specifications on the new Keyset ID V2, PR294 adds the new NUT-26, which defines an alternative encoding format for payment request using bech32m, and PR267 introduces NUT-27, which describes a method for wallets to backup their mint list as Nostr replaceable events on one or more relays.

  • Other changes were discussed, which are still work-in-progress. In particular, PR331 updates NUT-13, defining a way to generate private keys in a deterministic way to have proofs locked to them, and PR300 introduces NUT-28, which provides specifications for Pay-To-Blinded-Key (P2BK) payment type.

• PR370 in BDK aims to add support for Child-Pays-For-Parent (CPFP) transactions.

  • During the weekly meeting, on Tuesday 27th, BDK maintainers discussed PR370, which aims to add support for Child-Pays-For-Parent (CPFP) transactions. This feature is expected to be release in the next major release, v3.0.0.

  • CPFP is a fee bumping technique that allows a user to spend an output from a low feerate unconfirmed transaction (the “parent” transaction) in a “child” transaction with a higher feerate, incentivizing miners to include both transactions into a block. This feature has been available in Bitcoin Core since February 2016.

  • What is cool about the tech: This PR adds an important feature, increasing the number of tools available for wallet developers leveraging BDK.

• PR2049 in Stratum V2 aims to optimize the extranonce prefix generation.

  • During the weekly update, on Tuesday 27th, SV2 developers discussed PR2049, whose goal is to improve the way the extranonce_prefix is generated in the mining protocol.

  • The extranonce_prefix is a set of reserved bytes that allows any upstream node, like a pool or a proxy, to assign a unique identifier to each downstream connection (e.g. A miner). This way, a miner is guaranteed not to be working on the same hash as others.

  • While the extranonce_prefix would theoretically need only 2 bytes, the current generation method allocates a larger chunk of memory to avoid collisions, at the cost of coinbase space. The proposed method leverages a vector of bits where each prefix will be the index of an open slot in the vector. When a client disconnects, the bit is cleared, allowing it to be reused for another connection.

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.