Conduition, Ram, and Fabian Jahr joined Optech to discuss Newsletter #417: - Draft BIP for stale tip relay - CISA for taproot keypath spends (BIP460) - Segwit commitment to post-quantum witness data - PQC output type discussion - Input-triggered transaction expiry - Layered quantum recovery of hashed addresses - Segregated Data (SegData) BIP draft - And more You can listen on our website: https://bitcoinops.org/en/podcast/2026/08/11/ Fountain: https://fountain.fm/episode/X3dpYvlQy2N6tO4DeQl3 Spotify: https://open.spotify.com/episode/7wkE8AkAwXf7QIKlcO5cK4 Apple Podcasts: https://podcasts.apple.com/us/podcast/bitcoin-optech-newsletter-417-recap/id1674626983?i=1000782982957

Bitcoin Optech newsletter #417 is here: - describes a draft BIP for relaying stale block tips between peers - summarizes a draft BIP for cross-input signature aggregation - examines a design for attaching post-quantum witness data - links to a discussion of post-quantum output types - summarizes discussions around transaction expiry - points to a proposal for layered quantum recovery of hashed addresses - describes a proposal to add a prunable block region for arbitrary data - Optech Newsletter #417 Podcast https://bitcoinops.org/en/newsletters/2026/08/07/ Ram and w0xlt posted to the Bitcoin-Dev mailing list about the proposal for an opt-in P2P message for relaying stale tips between peers... https://bitcoinops.org/en/newsletters/2026/08/07/#draft-bip-for-stale-tip-relay Fabian Jahr posted to the Bitcoin-Dev mailing list a draft of BIP460 for transaction-wide cross-input signature aggregation (CISA) of taproot-style keypath spends... https://bitcoinops.org/en/newsletters/2026/08/07/#cisa-for-taproot-keypath-spends-bip460 Pieter Wuille posted to Delving Bitcoin a design for attaching post-quantum witness data without repeating all of segwit’s deployment costs... https://bitcoinops.org/en/newsletters/2026/08/07/#segwit-commitment-to-post-quantum-witness-data Pieter Wuille opened a Delving Bitcoin thread to centralize discussion of post-quantum output types... https://bitcoinops.org/en/newsletters/2026/08/07/#pqc-output-type-discussion Josh Doman posted to Delving Bitcoin a construction for expiring HTLCs without free relay, then generalized it in a follow-up on input-triggered transaction expiry... https://bitcoinops.org/en/newsletters/2026/08/07/#input-triggered-transaction-expiry Shinobi posted to the Bitcoin-Dev mailing list and cross-posted to Delving Bitcoin a layered recovery plan for coins secured by hashed address types... https://bitcoinops.org/en/newsletters/2026/08/07/#layered-quantum-recovery-of-hashed-addresses MrHash posted to Delving Bitcoin companion BIP drafts for Segregated Data, a soft fork that would add a prunable, script-isolated block region for arbitrary data carriage... https://bitcoinops.org/en/newsletters/2026/08/07/#segregated-data-segdata-bip-draft Bitcoin Optech will host an audio recap discussion of this newsletter streaming live on X/Twitter Tuesday at 16:30 UTC.

Rob Hamilton, PortlandHODL, Chandra Pratap, and fabohax joined Optech to discuss Newsletter #416: - Move funds secured by COLDCARD-generated keys - Wallets generated by COLDCARD at risk of theft - Disclosure of two DoS vulnerabilities in Core Lightning - Proof of concept for a zero-knowledge proof of reserves - Selected Q&A from the Bitcoin Stack Exchange - And more You can listen on our website: https://bitcoinops.org/en/podcast/2026/08/04/ Fountain: https://fountain.fm/show/nnl3QRRuNyxBry8BBoH4 Spotify: https://open.spotify.com/episode/3iTz1RULox5l93wkgqVtO9 Apple Podcasts: https://podcasts.apple.com/us/podcast/bitcoin-optech-newsletter-416-recap/id1674626983?i=1000780099759

Bitcoin Optech newsletter #416 is here: - warns about a severe vulnerability affecting wallets generated by COLDCARD signing devices - summarizes the disclosure of two denial-of-service vulnerabilities in Core Lightning - describes a proof of concept for a zero-knowledge proof of reserves - summarizes popular Q&A from Stack Exchange - Optech Newsletter #416 Podcast https://bitcoinops.org/en/newsletters/2026/07/31/ If you used a COLDCARD to generate a wallet, any funds received by that wallet are at risk of theft and should be carefully moved to an unaffected wallet as soon as possible... https://bitcoinops.org/en/newsletters/2026/07/31/#move-funds-secured-by-coldcard-generated-keys On 30 July 2026, some Bitcoin users discovered that funds from their COLDCARD wallets had been stolen in a series of unexpected transactions on 29 July. Over the course of the day, a bug was identified in the firmware of the COLDCARD that causes wallets to be generated with insufficient entropy. As of this writing, estimated losses exceed 1,000 BTC, a figure that may continue to rise as the situation develops... https://bitcoinops.org/en/newsletters/2026/07/31/#wallets-generated-by-coldcard-at-risk-of-theft Chandra Pratap posted to Delving Bitcoin about two denial-of-service (DoS) vulnerabilities he found in Core Lightning... https://bitcoinops.org/en/newsletters/2026/07/31/#disclosure-of-two-dos-vulnerabilities-in-core-lightning fabohax posted about zkPoH (“zero-knowledge proof-of-hodl”), a proof of concept for a non-custodial proof of reserves system for Bitcoin... https://bitcoinops.org/en/newsletters/2026/07/31/#proof-of-concept-for-a-zero-knowledge-proof-of-reserves Selected Q&A from Bitcoin Stack Exchange - What is Bitcoin’s objective definition of transaction neutrality? - Why does BIP110’s decentralization benefit not outweigh its impact on transaction neutrality? - Why does BIP110 require a 55% signaling threshold if its nodes reject non-signaling blocks? - Why use ElligatorSwift encoding in BIP324? - Was the OP_SUCCESSx reservation in BIP342 designed with specific opcode families in mind? - What is the difference between the long-term feerate and the discard feerate? - What is the quickest method for migrating a legacy wallet to a descriptor wallet on a pruned node? - Is there historical data on orphan/stale block rates during high-fee periods? https://bitcoinops.org/en/newsletters/2026/07/31/#selected-qa-from-bitcoin-stack-exchange Bitcoin Optech will host an audio recap discussion of this newsletter streaming live on X/Twitter Tuesday at 16:30 UTC.

PSA: Wallets generated by Coldcard at risk! Wallets generated by Coldcard Mk3 using a firmware version 4.0.1 (March 2021) or later, up to the latest version may be vulnerable to theft, unless used in combination with a strong passphrase or entropy was generated externally. Please see the Coinkite security advisory (https://blog.coinkite.com/coldcard-mk3-seed-generation-warning/). The attack is easy to reproduce with LLM assistance. There are reports that Mk2, Mk4, and Mk5 may be affected by (weaker) variants of the same vulnerability. If your wallet may be affected, please carefully move your funds to an unaffected wallet ASAP.

Fabian Jahr, Kruw, and Mojo joined Optech to discuss Newsletter #415: - Draft BIP for full aggregation of BIP340 signatures - Changes to services and client software including Wasabi, Coinswap, Go secp256k1, an ASMap dashboard, Wavelength - And more You can listen on our website: https://bitcoinops.org/en/podcast/2026/07/28/ Fountain: https://fountain.fm/episode/DwKaI4UBnN19MQJpcEPx Spotify: https://open.spotify.com/episode/6Dq72RsD8V9OxhdLc7UV7B Apple Podcasts: https://podcasts.apple.com/us/podcast/bitcoin-optech-newsletter-415-recap/id1674626983?i=1000778755233

Bitcoin Optech newsletter #415 is here: - describes a draft BIP for full aggregation of BIP340 signatures - summarizes changes to services/client software - Optech Newsletter #415 Podcast https://bitcoinops.org/en/newsletters/2026/07/24/ Fabian Jahr posted to the Bitcoin-Dev mailing list about a new draft BIP for full aggregation of BIP340 schnorr signatures, a standard for the DahLIAS aggregate signature scheme... https://bitcoinops.org/en/newsletters/2026/07/24/#draft-bip-for-full-aggregation-of-bip340-signatures Changes to services and client software: - Wasabi Wallet 2.8.0 released - Coinswap v0.2.2 released - Go secp256k1 library announced - ASMap dashboard announced - Wavelength alpha released https://bitcoinops.org/en/newsletters/2026/07/24/#changes-to-services-and-client-software Bitcoin Optech will host an audio recap discussion of this newsletter streaming live on X/Twitter Tuesday at 16:30 UTC.

Keagan McClelland and Andrew Toth joined Optech to discuss Newsletter #414: - Formal verification of the Bitcoin protocol - Bitcoin Core 30.3, Bitcoin Core 29.4 - Parallel input fetching in Bitcoin Core - And more You can listen on our website: https://bitcoinops.org/en/podcast/2026/07/21/ Fountain: https://fountain.fm/episode/CvNXTopIBoxJuLpmT8Sg Spotify: https://open.spotify.com/episode/3sUFnSFebB8Ff3takKKqVZ Apple Podcasts: https://podcasts.apple.com/us/podcast/bitcoin-optech-newsletter-414-recap/id1674626983?i=1000777771807

Bitcoin Optech newsletter #414 is here: - describes a new project to apply formal verification to the Bitcoin protocol - Bitcoin Core 30.3, Bitcoin Core 29.4 - Optech Newsletter #414 Podcast https://bitcoinops.org/en/newsletters/2026/07/17/ Keagan McClelland posted to the Bitcoin-Dev mailing list and Delving Bitcoin about his effort to formally verify the Bitcoin protocol... https://bitcoinops.org/en/newsletters/2026/07/17/#formal-verification-of-the-bitcoin-protocol Bitcoin Optech will host an audio recap discussion of this newsletter streaming live on X/Twitter Tuesday at 16:30 UTC.