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 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

Earlier today Daniela Brozzoni and Naiyoma joined and 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 Catch up: https://bitcoinops.org/en/podcast/2025/07/01/

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 us to discuss or ask questions! https://riverside.fm/studio/bitcoin-optech

Earlier today, Bryan Bishop, Robin Linus, and Rene Pickhardt joined and 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/

Earlier today, Antoine Poinsot, Peter Todd, Josh Doman, and TheCharlatan joined us to discuss Newsletter #358: - Selfish mining - Transaction relay censorship resistance - Updates to BIP390 - Encrypting descriptors - The bitcoinkernel project - And more Catch up: https://bitcoinops.org/en/podcast/2025/06/17/

Jose SK, Clara Shikhelman, Vojtěch Strnad, Robin Linus, and Dan Gould joined and to discuss: - Syncing full nodes without witnesses - Quantum computing report - Transaction weight limit with exception to prevent confiscation - Removing outputs from the UTXO set based on value and time - And More… Catch up: https://bitcoinops.org/en/podcast/2025/06/10/