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bitcoin

Josh Doman and Gloria Zhao joined Optech to discuss ⁠⁠Newsletter #362⁠⁠:

- Compressing script descriptors
- A PR review club about orphans in Bitcoin Core
- And our usual releases and notable code segments



Bitcoin Optech Newsletter #362 Recap Podcast

Bitcoin Optech newsletter #362 is here:

- briefly describes a new library allowing output script descriptors to be compressed for use in QR codes
- recaps the "Improve TxOrphanage denial of service bounds" PR Review Meeting
- #362 Recap Podcast
https://bitcoinops.org/en/newsletters/2025/07/11/

Josh Doman posted to Delving Bitcoin to announce a library he’s written that encodes output script descriptors into a binary format that reduces their size by about 40%...
https://bitcoinops.org/en/newsletters/2025/07/11/#compressed-descriptors

Improve TxOrphanage denial of service bounds is a PR by glozow that changes TxOrphanage eviction logic to guarantee each peer the resources for at least 1 maximum-size package worth of orphan resolution...
https://bitcoinops.org/en/newsletters/2025/07/11/#bitcoin-core-pr-review-club

Bitcoin Optech will host an audio recap discussion of this newsletter on Riverside.fm Tuesday at 16:30 UTC. Join us to discuss or ask questions!
https://riverside.fm/studio/bitcoin-optech

Bitcoin Optech Newsletter #362

Sanket Kanjalkar, Jonas Nick, Tadge Dryja, Steven Roose, and Brandon Black joined Optech this week to discuss:

- A new onion message network
- CTV+CSFS and benefits to PTLCs and BitVM
- Vault descriptors
- The CTV and CSFS open letter
- Winternitz signatures using OP_CAT
- Commit/reveal function for post-quantum recovery
- OP_TXHASH variant with support for transaction sponsorship
- And more

https://bitcoinops.org/en/podcast/2025/07/08/

Bitcoin Optech Newsletter #361 Recap Podcast

Bitcoin Optech newsletter #361 is here:

- describes a proposal to separate the network connections and peer management used for onion message relay from those used for HTLC relay in LN
- CTV+CSFS advantages for PTLCs
- Vault output script descriptor
- Continued discussion about CTV+CSFS advantages for BitVM
- Open letter about CTV and CSFS
- OP_CAT enables Winternitz signatures
- Commit/reveal function for post-quantum recovery
- OP_TXHASH variant with support for transaction sponsorship
- Optech Newsletter #361 Recap Podcast
https://bitcoinops.org/en/newsletters/2025/07/04/

Olaluwa Osuntokun posted to Delving Bitcoin about allowing nodes to use separate connections for relaying onion messages than they use for relaying HTLCs...
https://bitcoinops.org/en/newsletters/2025/07/04/#separating-onion-message-relay-from-htlc-relay

Developers continued a previous discussion about the benefits of OP_CHECKTEMPLATEVERIFY (CTV), OP_CHECKSIGFROMSTACK (CSFS), or both together for various deployed and imagined protocols...
https://bitcoinops.org/en/newsletters/2025/07/04/#ctv-csfs-advantages-for-ptlcs

Sjors Provoost posted to Delving Bitcoin to discuss how the recovery information for a wallet using vaults could be specified using an output script descriptor...
https://bitcoinops.org/en/newsletters/2025/07/04/#vault-output-script-descriptor

Developers continued the previous discussion about how the availability of OP_CHECKTEMPLATEVERIFY (CTV) and OP_CHECKSIGFROMSTACK (CSFS) opcodes could “reduce [BitVM] transaction sizes by approximately 10x” and allow non-interactive peg-ins...
https://bitcoinops.org/en/newsletters/2025/07/04/#continued-discussion-about-ctv-csfs-advantages-for-bitvm

James O’Beirne posted an open letter to the Bitcoin-Dev mailing signed by 66 individuals (as of this writing), many of them contributors to Bitcoin-related projects...
https://bitcoinops.org/en/newsletters/2025/07/04/#open-letter-about-ctv-and-csfs

Developer Conduition posted to the Bitcoin-Dev mailing list a prototype implementation that uses the proposed OP_CAT opcode and other Script instructions to allow quantum-resistant signatures using the Winternitz protocol to be verified by consensus logic...
https://bitcoinops.org/en/newsletters/2025/07/04/#op-cat-enables-winternitz-signatures

Tadge Dryja posted to the Bitcoin-Dev mailing list a method for allowing individuals to spend UTXOs using quantum-vulnerable signature algorithms even if fast quantum computers would otherwise allow redirecting (stealing) the output of any attempted spend...
https://bitcoinops.org/en/newsletters/2025/07/04/#commit-reveal-function-for-post-quantum-recovery

Steven Roose posted to Delving Bitcoin about a variation on OP_TXHASH called TXSIGHASH that extends 64-byte schnorr signatures with additional bytes to indicate what fields in the transaction (or related transactions) the signature commits to...
https://bitcoinops.org/en/newsletters/2025/07/04/#op-txhash-variant-with-support-for-transaction-sponsorship

Bitcoin Optech will host an audio recap discussion of this newsletter on Riverside.fm Tuesday at 16:30 UTC. Join us to discuss or ask questions!
https://riverside.fm/studio/bitcoin-optech

Changing Consensus - Bitcoin Optech Newsletter #361

Daniela Brozzoni and Naiyoma joined Murch and Schmidty to discuss Newsletter #360:

- Fingerprinting Bitcoin Core nodes
- Descriptors and BIP380
- Questions from the bitcoin stack exchange about blocking knots nodes, OP_CAT, compact blocks, selfish mining
- And more

https://bitcoinops.org/en/podcast/2025/07/01/

Bitcoin Optech Newsletter #360 Recap Podcast

Bitcoin Optech Newsletter #360

Join us!

We have timestamps on the show pages to find what you like and skip around.

A week or so after publication we also have transcripts if you prefer to read or search.

Bitcoin Optech newsletter #360 is here:

- summarizes research about fingerprinting full nodes using P2P protocol messages
- seeks feedback about possibly removing support for H in BIP32 paths in the BIP380 specification of descriptors
- summarizes popular Q&A from Stack Exchange
- Optech Newsletter #360 Recap Podcast
https://bitcoinops.org/en/newsletters/2025/06/27/

Daniela Brozzoni posted to Delving Bitcoin about research she conducted with developer Naiyoma into identifying the same node on multiple networks using the addr messages it sends...
https://bitcoinops.org/en/newsletters/2025/06/27/#fingerprinting-nodes-using-addr-messages

Ava Chow posted to the Bitcoin-Dev mailing list to ask whether any software generates descriptors using uppercase-H to indicate a hardened BIP32 key derivation step...
https://bitcoinops.org/en/newsletters/2025/06/27/#does-any-software-use-h-in-descriptors

Selected Q&A from Bitcoin Stack Exchange:

- Is there any way to block Bitcoin Knots nodes as my peers?
- What does OP_CAT do with integers?
- Async Block Relaying With Compact Block Relay (BIP152) 
- Why is attacker revenue in selfish mining disproportional to its hash-power?
https://bitcoinops.org/en/newsletters/2025/06/27/#selected-qa-from-bitcoin-stack-exchange

Bitcoin Optech will host an audio recap discussion of this newsletter on Riverside.fm Tuesday at 16:30 UTC. Join to discuss or ask questions!
https://riverside.fm/studio/bitcoin-optech


tech

Earlier today, Bryan Bishop, Robin Linus, and Rene Pickhardt joined Murch and Schmidty to cover:

- Restricting access to Bitcoin Core Project discussion
- Garbled circuits and BitVM3
- Updates on Lightning channel rebalancing research 
- Cove Wallet, Liana, Stratum v2 STARK proofs, Breez
- And more!

Catch up:
https://bitcoinops.org/en/podcast/2025/06/24/