Bitcoin Optech Newsletter #424

AI editorial brief — source checked

This week's Bitcoin Optech Newsletter #424 details Ahmet Kurt's proposal for upgrading the Lightning Network to post-quantum security (PQLN), covering modifications to gossip, transport, invoices, offers, and onion layers. It notes the transition's bandwidth cost (10x download, 9x storage) and minimal computation impact. The newsletter also includes Stack Exchange Q&A, release candidates for Bitcoin Core 32.0rc2, Core Lightning 26.06.8, and LDK v0.3-rc2, and notable code changes across infrastructure projects.

1. The ML-DSA-44 signature, which has a size of 2420 bytes, must be split across 4 different fields in BOLT11 invoices due to the 639-byte tagged field limit.
   Source evidence

   ● Invoices (BOLT11): Since a tagged field in an invoice holds at most 639 bytes, the ML-DSA-44 signature, which has a size of 2420 bytes, must be split across 4 different fields.
2. According to Kurt, the real cost of this transition is bandwidth. A node needs to download 10 times and store 9 times the data of a simple LN node.
   Source evidence

   According to Kurt, the real cost of this transition is bandwidth. A node needs to download 10 times and store 9 times the data of a simple LN node. On the other hand, computation is not an
3. Core Lightning 26.06.8 is a security release of this popular LN node implementation. It includes bug fixes for responsibly reported vulnerabilities.
   Source evidence

   ● Core Lightning 26.06.8 is a security release of this popular LN node implementation. It includes bug fixes for responsibly reported vulnerabilities. The source code is available immediately.
4. LDK v0.3-rc2 is a second release candidate for the next major version of this library for building LN-enabled wallets and applications. It adds RBF fee bumping for pending splices and support for adding and removing funds in the same splice.
   Source evidence

   ● LDK v0.3-rc2 is a second release candidate for the next major version of this library for building LN-enabled wallets and applications. It adds RBF fee bumping for pending splices and support
5. Bitcoin Core #34566 adds multi-signet data directory support, allowing custom signets to share a base data directory without their chain data conflicting.
   Source evidence

   ● Bitcoin Core #34566 adds multi-signet data directory support (see Newsletter #412), allowing custom signets to share a base data directory without their chain data conflicting. Each custom

What remains uncertain: The newsletter does not establish whether the PQLN proposal has been adopted or implemented beyond testing, nor does it confirm the timeline for deployment or consensus on feature bits and TLV types for the post-quantum Lightning Network.