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

Bitcoin Optech

Bitcoin Optech Newsletter #360

This week’s newsletter summarizes research about fingerprinting full nodes using P2P protocol messages and seeks feedback about possibly removing...

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...

Bitcoin Optech

Bitcoin Optech Newsletter #360

This week’s newsletter summarizes research about fingerprinting full nodes using P2P protocol messages and seeks feedback about possibly removing...

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...

Bitcoin Optech

Bitcoin Optech Newsletter #360

This week’s newsletter summarizes research about fingerprinting full nodes using P2P protocol messages and seeks feedback about possibly removing...

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?

Bitcoin Optech

Bitcoin Optech Newsletter #360

This week’s newsletter summarizes research about fingerprinting full nodes using P2P protocol messages and seeks feedback about possibly removing...

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!

Riverside.FM Studio

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:

Bitcoin Optech

Bitcoin Optech Newsletter #359 Recap Podcast

Mark “Murch” Erhardt and Mike Schmidt are joined by Bryan Bishop, Robin Linus, and Rene Pickhardt to discuss Newsletter #359.

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:

Bitcoin Optech

Bitcoin Optech Newsletter #358 Recap Podcast

Mark “Murch” Erhardt and Mike Schmidt are joined by Antoine Poinsot, Peter Todd, Josh Doman, and TheCharlatan to discuss Newsletter #358.

Bitcoin Optech newsletter #358 is here: - describes how the selfish mining danger threshold can be calculated - summarizes an idea about preventing filtering of high feerate transactions - seeks feedback about a proposed change to BIP390 musig() descriptors - announces a new library for encrypting descriptors - recaps the "Separate UTXO set access from validation functions" PR Review Meeting - adds a Selfish Mining topic - Optech Newsletter #358 Recap

Bitcoin Optech

Bitcoin Optech Newsletter #358

This week’s newsletter describes how the selfish mining danger threshold can be calculated, summarizes an idea about preventing filtering of high...

Antoine Poinsot posted to Delving Bitcoin an expansion of the math from the 2013 paper that gave the selfish mining attack its name...

Bitcoin Optech

Bitcoin Optech Newsletter #358

This week’s newsletter describes how the selfish mining danger threshold can be calculated, summarizes an idea about preventing filtering of high...

Peter Todd posted to the Bitcoin-Dev mailing list about a mechanism that would allow nodes to drop peers that are filtering high-feerate transactions...

Bitcoin Optech

Bitcoin Optech Newsletter #358

This week’s newsletter describes how the selfish mining danger threshold can be calculated, summarizes an idea about preventing filtering of high...

Ava Chow posted to the Bitcoin-Dev mailing list to ask if anyone objected to updating BIP390 to allow musig() expressions in output script descriptors to contain the same participant public key more than once...

Bitcoin Optech

Bitcoin Optech Newsletter #358

This week’s newsletter describes how the selfish mining danger threshold can be calculated, summarizes an idea about preventing filtering of high...

Josh Doman posted to Delving Bitcoin to announce a library he’s built that encrypts the sensitive parts of an output script descriptor or miniscript to the public keys contained within it...

Bitcoin Optech

Bitcoin Optech Newsletter #358

This week’s newsletter describes how the selfish mining danger threshold can be calculated, summarizes an idea about preventing filtering of high...

'Separate UTXO set access from validation functions' is a PR by TheCharlatan that allows calling validation functions by passing just the required UTXOs, instead of requiring the complete UTXO set. It is part of the bitcoinkernel project...

Bitcoin Optech

Bitcoin Optech Newsletter #358

This week’s newsletter describes how the selfish mining danger threshold can be calculated, summarizes an idea about preventing filtering of high...

Selfish mining allows a miner (or cartel of miners) controlling less than a majority of hashrate to keep more block reward per unit of work than the majority of honest miners...

Bitcoin Optech

Selfish mining

Selfish mining allows a miner (or cartel of miners) controlling less than a majority of hashrate to keep more block reward per unit of work than th...

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!

Riverside.FM Studio

Jose SK, Clara Shikhelman, Vojtěch Strnad, Robin Linus, and Dan Gould joined @Murch and @schmidty 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:

Bitcoin Optech

Bitcoin Optech Newsletter #357 Recap Podcast

Mark “Murch” Erhardt and Mike Schmidt are joined by Jose SK, Clara Shikhelman, Vojtěch Strnad, Robin Linus, and Dan Gould to discuss Newslette...

Bitcoin Optech newsletter #357 is here: - shares an analysis about syncing full nodes without old witnesses - Changing consensus covering: a quantum computing report, transaction weight limits, removing outputs from the UTXO set based on value and time - Optech Newsletter #357 Recap

Bitcoin Optech

Bitcoin Optech Newsletter #357

This week’s newsletter shares an analysis about syncing full nodes without old witnesses. Also included are our regular sections with description...

Jose SK posted to Delving Bitcoin a summary of an analysis he performed about the security tradeoffs of allowing newly started full nodes with a particular configuration to avoid downloading some historic blockchain data...

Bitcoin Optech

Bitcoin Optech Newsletter #357

This week’s newsletter shares an analysis about syncing full nodes without old witnesses. Also included are our regular sections with description...

Clara Shikhelman posted to Delving Bitcoin the summary of a report she co-authored with Anthony Milton about the risks to Bitcoin users of fast quantum computers, an overview of several pathways to quantum resistance, and an analysis of tradeoffs involved in upgrading the Bitcoin protocol...

Bitcoin Optech

Bitcoin Optech Newsletter #357

This week’s newsletter shares an analysis about syncing full nodes without old witnesses. Also included are our regular sections with description...

Vojtěch Strnad posted to Delving Bitcoin to propose the idea for a consensus change to limit the maximum weight of most transactions in a block...

Bitcoin Optech

Bitcoin Optech Newsletter #357

This week’s newsletter shares an analysis about syncing full nodes without old witnesses. Also included are our regular sections with description...

Robin Linus posted to Delving Bitcoin to propose a soft fork for removing low-value outputs from the UTXO set after some time...

Bitcoin Optech

Bitcoin Optech Newsletter #357

This week’s newsletter shares an analysis about syncing full nodes without old witnesses. Also included are our regular sections with description...

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!

Riverside.FM Studio

Earlier today, @Murch and @schmidty were joined by Carla Kirk-Cohen, Joost Jager, and Elias Rohrer to discuss #356: - Attributable failures and LN privacy - Several P2P and policy questions from the Bitcoin Stack Exchange - And more! Catch up:

Bitcoin Optech

Bitcoin Optech Newsletter #356 Recap Podcast

Mark “Murch” Erhardt and Mike Schmidt are joined by Carla Kirk-Cohen, Joost Jager, and Elias Rohrer to discuss Newsletter #356.

Last week Dave Harding was joined by Alex Myers and Rodolfo Novak to discuss Newsletter #355: - Cake Wallet, Sparrow, Safe Wallet, COLDCARD, tx batching using payjoin, JoinMarket fidelity bonds, Bitcoin opcode documentation, Bitkey open sourced - LND and CLN releases - Bitcoin Core, CLN and LND PRs Catch up:

Bitcoin Optech

Bitcoin Optech Newsletter #355 Recap Podcast

Dave Harding is joined by Alex Myers and Rodolfo Novak to discuss Newsletter #355.

Bitcoin Optech newsletter #356 is here: - summarizes a discussion about the possible effects of attributable failures on LN privacy - summarizes popular Q&A from Stack Exchange - adds an attributable failures topic - Optech Newsletter #356 Recap Podcast

Bitcoin Optech

Bitcoin Optech Newsletter #356

This week’s newsletter summarizes a discussion about the possible effects of attributable failures on LN privacy. Also included are our regular s...

Carla Kirk-Cohen posted to Delving Bitcoin an analysis of the possible consequences for the privacy of LN spenders and receivers if the network adopts attributable failures, particularly telling the spender the amount of time it took to forward a payment at each hop...

Bitcoin Optech

Bitcoin Optech Newsletter #356

This week’s newsletter summarizes a discussion about the possible effects of attributable failures on LN privacy. Also included are our regular s...

Selected Q&A from Bitcoin Stack Exchange: - Which transactions get into blockreconstructionextratxn? - Why would anyone use OP_RETURN over inscriptions, aside from fees? - Why is my Bitcoin node not receiving incoming connections? - How do I configure my node to filter out transactions larger than 400 bytes? - What does “not publicly routable” node in Bitcoin Core P2P mean? - Why would a node would ever relay a transaction? - Is selfish mining still an option with compact blocks and FIBRE?

Bitcoin Optech

Bitcoin Optech Newsletter #356

This week’s newsletter summarizes a discussion about the possible effects of attributable failures on LN privacy. Also included are our regular s...

Attributable failures are LN payment forwarding failures or delays that can be attributed to a pair of nodes, allowing spenders to avoid using slow or failure-prone nodes for future payments...

Bitcoin Optech

Attributable failures

Attributable failures are LN payment forwarding failures or delays that can be attributed to a pair of nodes (who may have one or more channels bet...

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!

Riverside.FM Studio

Bitcoin Optech newsletter #355 is here: - summarizes changes to services/client software - LND 0.19.0-beta, Core Lightning 25.05rc1 releases - Optech Newsletter #355 Recap Podcast

Bitcoin Optech

Bitcoin Optech Newsletter #355

This week’s newsletter includes our regular sections describing changes to services and client software, announcing new releases and release cand...

Changes to services and client software: - Cake Wallet added payjoin v2 support - Sparrow adds pay-to-anchor features - Safe Wallet 1.3.0 released - COLDCARD Q v1.3.2 released - Transaction batching using payjoin - JoinMarket Fidelity Bond Simulator - Bitcoin opcodes documented - Bitkey code open sourced

Bitcoin Optech

Bitcoin Optech Newsletter #355

This week’s newsletter includes our regular sections describing changes to services and client software, announcing new releases and release cand...

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!

Riverside.FM Studio

Yesterday @Murch @schmidty spoke with Eugene Siegel, Chris Stewart, Bram Cohen, and Robin Linus: - A disclosed Bitcoin Core vulnerability - 64 bit arithmetic draft BIP - A new approach to recursive covenants - BitVM benefits from CTV and CSFS - And more Catch up:

Bitcoin Optech

Bitcoin Optech Newsletter #354 Recap Podcast

Mark “Murch” Erhardt and Mike Schmidt are joined by Eugene Siegel, Chris Stewart, Bram Cohen, and Robin Linus to discuss Newsletter #354.

Bitcoin Optech newsletter #354 is here: - describes a fixed vulnerability affecting old versions of Bitcoin Core - Changing consensus covering: 64-bit arithmetic in Script, Proposed opcodes for enabling recursive covenants through quines, benefits to BitVM from OP_CTV and OP_CSFS - Optech Newsletter #354 Recap Podcast

Bitcoin Optech

Bitcoin Optech Newsletter #354

This week’s newsletter describes a fixed vulnerability affecting old versions of Bitcoin Core. Also included are our regular sections summarizing...

Antoine Poinsot posted to the Bitcoin-Dev mailing list to announce a vulnerability affecting Bitcoin Core versions before 29.0...

Bitcoin Optech

Bitcoin Optech Newsletter #354

This week’s newsletter describes a fixed vulnerability affecting old versions of Bitcoin Core. Also included are our regular sections summarizing...

Chris Stewart posted a draft BIP to the Bitcoin-Dev mailing list that proposes upgrading Bitcoin’s existing opcodes to operate on 64-bit numeric values...

Bitcoin Optech

Bitcoin Optech Newsletter #354

This week’s newsletter describes a fixed vulnerability affecting old versions of Bitcoin Core. Also included are our regular sections summarizing...

Bram Cohen posted to Delving Bitcoin to suggest a set of simple opcodes that would enable the creation of recursive covenants through self-reproducing scripts (quines)...

Bitcoin Optech

Bitcoin Optech Newsletter #354

This week’s newsletter describes a fixed vulnerability affecting old versions of Bitcoin Core. Also included are our regular sections summarizing...

Robin Linus posted to Delving Bitcoin about several of the improvements to BitVM that would become possible if the proposed OP_CTV and OP_CSFS opcodes were added to Bitcoin in a soft fork...

Bitcoin Optech

Bitcoin Optech Newsletter #354

This week’s newsletter describes a fixed vulnerability affecting old versions of Bitcoin Core. Also included are our regular sections summarizing...

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!

Riverside.FM Studio

Earlier this week @Murch and @schmidty discussed Newsletter #353 with Ruben Somsen, Salvatore Ingala, and Stéphan Vuylsteke: - BIP30 consensus failure vulnerability - Avoiding BIP32 path reuse - Bitcoin Core’s multiprocess project - And more… Catch up:

Bitcoin Optech

Bitcoin Optech Newsletter #353 Recap Podcast

Mark “Murch” Erhardt and Mike Schmidt are joined by Ruben Somsen, Salvatore Ingala, and Stéphan Vuylsteke to discuss Newsletter #353.

Earlier this week @Murch and @Sjors Provoost discussed Newsletter #352: - Cluster linearization techniques for cluster mempool - Increasing or removing Bitcoin Core’s OP_RETURN size limit - Bitcoin Core removing legacy wallets - And more... Catch up:

Bitcoin Optech

Bitcoin Optech Newsletter #352 Recap Podcast

Mark “Murch” Erhardt and Sjors Provoost discuss Newsletter #352.

Bitcoin Optech newsletter #353 is here: - describes a recently discovered theoretical consensus failure vulnerability - links to a proposal to avoid reuse of BIP32 wallet paths - recaps the "Add bitcoin wrapper executable" PR Review Meeting - Optech Newsletter #353 Recap

Bitcoin Optech

Bitcoin Optech Newsletter #353

This week’s newsletter describes a recently discovered theoretical consensus failure vulnerability and links to a proposal to avoid reuse of BIP3...

Ruben Somsen posted to the Bitcoin-Dev mailing list about a theoretical consensus failure that could occur now that checkpoints have been removed from Bitcoin Core...

Bitcoin Optech

Bitcoin Optech Newsletter #353

This week’s newsletter describes a recently discovered theoretical consensus failure vulnerability and links to a proposal to avoid reuse of BIP3...

Kevin Loaec posted to Delving Bitcoin to discuss options for preventing the same BIP32 wallet path from being used with different wallets, which could lead to a loss of privacy due to output linking and a theoretical loss of security...

Bitcoin Optech

Bitcoin Optech Newsletter #353

This week’s newsletter describes a recently discovered theoretical consensus failure vulnerability and links to a proposal to avoid reuse of BIP3...

"Add bitcoin wrapper executable" is a PR by ryanofsky that introduces a new bitcoin binary which can be used to discover and launch the various Bitcoin Core binaries...

Bitcoin Optech

Bitcoin Optech Newsletter #353

This week’s newsletter describes a recently discovered theoretical consensus failure vulnerability and links to a proposal to avoid reuse of BIP3...

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!

Riverside.FM Studio

Bitcoin Optech newsletter #352 is here: - links to comparisons between different cluster linearization techniques - briefly summarizes discussion about increasing or removing Bitcoin Core’s OP_RETURN size limit - Optech Newsletter #352 Recap

Bitcoin Optech

Bitcoin Optech Newsletter #352

This week’s newsletter links to comparisons between different cluster linearization techniques and briefly summarizes discussion about increasing...

Pieter Wuille posted to Delving Bitcoin about some of the fundamental tradeoffs between three different cluster linearization techniques, following up with benchmarks of implementations of each...

Bitcoin Optech

Bitcoin Optech Newsletter #352

This week’s newsletter links to comparisons between different cluster linearization techniques and briefly summarizes discussion about increasing...

In a thread on Bitcoin-Dev, several developers discussed changing or removing Bitcoin Core’s default limit for OP_RETURN data carrier outputs. A subsequent Bitcoin Core pull request saw additional discussion...

Bitcoin Optech

Bitcoin Optech Newsletter #352

This week’s newsletter links to comparisons between different cluster linearization techniques and briefly summarizes discussion about increasing...

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!

Riverside.FM Studio

Yesterday @Murch and @schmidty had on Jonas Nick and Salvatore Ingala to cover Newsletter #351: - The DahLIAS Interactive aggregate signatures compatible with secp256k1 - Standardized backup for wallet descriptors - Stack Exchange questions including: half-aggregated schnorr signatures, OP_RETURN, reorg statistics, and more Catch up:

Bitcoin Optech

Bitcoin Optech Newsletter #351 Recap Podcast

Mark “Murch” Erhardt and Mike Schmidt are joined by Jonas Nick and Salvatore Ingala to discuss Newsletter #351.

Bitcoin Optech newsletter #351 is here: - announces a new aggregate signature protocol compatible with secp256k1 - describes a standardized backup scheme for wallet descriptors - summarizes popular Q&A from Stack Exchange - Optech Newsletter #351 Recap

Bitcoin Optech

Bitcoin Optech Newsletter #351

This week’s newsletter announces a new aggregate signature protocol compatible with secp256k1 and describes a standardized backup scheme for wall...

Jonas Nick, Tim Ruffing, Yannick Seurin posted to the Bitcoin-Dev mailing list to announce a paper they’ve written about creating 64-byte aggregate signatures compatible with the cryptographic primitives already used by Bitcoin...

Bitcoin Optech

Bitcoin Optech Newsletter #351

This week’s newsletter announces a new aggregate signature protocol compatible with secp256k1 and describes a standardized backup scheme for wall...

Salvatore Ingala posted to Delving Bitcoin a summary of various tradeoffs related to backing up wallet descriptors and a proposed scheme that should be useful for many different types of wallets, including those using complex scripts...

Bitcoin Optech

Bitcoin Optech Newsletter #351

This week’s newsletter announces a new aggregate signature protocol compatible with secp256k1 and describes a standardized backup scheme for wall...

Selected Q&A from Bitcoin Stack Exchange: - Practicality of half-aggregated schnorr signatures? - What’s the largest size OP_RETURN payload ever created? - Non-LN explanation of pay-to-anchor? - Up-to-date statistics about chain reorganizations? - Are Lightning channels always P2WSH? - Child-pays-for-parent as a defense against a double spend? - What values does CHECKTEMPLATEVERIFY hash? - Why can’t Lightning nodes opt to reveal channel balances for better routing efficiency? - Does post-quantum require hard fork or soft fork?

Bitcoin Optech

Bitcoin Optech Newsletter #351

This week’s newsletter announces a new aggregate signature protocol compatible with secp256k1 and describes a standardized backup scheme for wall...

Bitcoin Optech will host an audio recap discussion of this newsletter on Riverside.fm Tuesday at 15:30 UTC. Join us to discuss or ask questions!

Riverside.FM Studio

Earlier today @Murch and @schmidty spoke with Niklas Gögge about Newsletter #350: - Fuzz testing tool for Bitcoin nodes - Message signing - PSBTv2 explorer - MPC Library - Bitcoin Core 29.0 - And more! Catch up:

Bitcoin Optech

Bitcoin Optech Newsletter #350 Recap Podcast

Mark “Murch” Erhardt and Mike Schmidt are joined by Niklas Gögge to discuss Newsletter #350.

Last week @Murch and @David A. Harding spoke with Sebastian Falbesoner, Ruben Somsen, and Abubakar Sadiq Ismail about Newsletter #349: - IBD using SwiftSync - Bitcoin Core fee estimation - And more! Catch up:

Bitcoin Optech

Bitcoin Optech Newsletter #349 Recap Podcast

Mark “Murch” Erhardt and Dave Harding are joined by Sebastian Falbesoner, Ruben Somsen, and Abubakar Sadiq Ismail to discuss Newsletter #349.