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Bitcoin Optech
_@bitcoinops.org
npub1hkuk...432p
We provide weekly newsletters, workshops, case studies, and research for the #Bitcoin community.
Bitcoin Optech newsletter #385: 2025 Year-in-Review Special is here: - notes Bitcoin developments during each month of 2025 - feature: Vulnerability disclosures - feature: Quantum - feature: Soft fork proposals - feature: Stratum v2 - feature: Major releases of popular infrastructure projects - feature: Optech In 2025, Optech summarized more than a dozen vulnerability disclosures... With the increased attention on the potential for a future quantum computer to weaken or break the Elliptic Curve Discrete Logarithm (ECDL) hardness assumption that Bitcoin relies on to prove the ownership of coins, several conversations and proposals were put forward throughout the year to discuss and mitigate the impact of such a development. This year saw a bevy of discussions around soft fork proposals, ranging from the tightly scoped and minimally impactful, to the broadly scoped and powerful… Stratum v2 is a mining protocol designed to replace the original Stratum protocol used between miners and mining pools. Throughout 2025, Bitcoin Core received several updates to better support Stratum v2 implementations.... Optech covered major releases of popular infrastructure projects throughout the year... In Optech’s eighth year, we published: - 50 newsletters - over 80,000 words, a 225pg book equivalent - over 60hrs of podcasts, with 500,000 words of transcripts w/75 guests - 150+ non-English translations A special thank you After contributing as the primary author for 376 consecutive Bitcoin Optech newsletters, Dave Harding stepped back from contributing regularly this year. We cannot thank Harding enough for anchoring the newsletter for eight years and all of the Bitcoin education, elucidation, and understanding he brought the community. We are eternally grateful and wish him all the best. Bitcoin Optech will host an audio recap discussion of this special newsletter on Riverside.fm Tuesday at 17:30 UTC. Join us to discuss or ask questions!
Bitcoin Optech newsletter #384 is here: - discloses vulnerabilities in LND - describes a project for running a virtual machine in an embedded secure element - summarizes changes to services/client software - summarizes popular Q&A from Stack Exchange - Optech Newsletter #384 Podcast Matt Morehouse posted to Delving Bitcoin about critical vulnerabilities fixed in LND 0.19.0... Salvatoshi posted to Delving Bitcoin about Vanadium, a virtualized secure enclave for hardware signing devices... Changes to services and client software: - Interactive transaction visualization tool - BlueWallet v7.2.2 released - Stratum v2 updates - Auradine announces Stratum v2 support - LDK Node 0.7.0 released - BIP-329 Python Library 1.0.0 release - Bitcoin Safe 1.6.0 released Selected Q&A from Bitcoin Stack Exchange: - Does a clearnet connection to my Lightning node require a TLS certificate? - Why do different implementations produce different DER signatures for the same private key and hash? - Why is the miniscript after value limited at 0x80000000? Bitcoin Optech will host an audio recap discussion of this newsletter on Tuesday at 17:30 UTC. Join us to discuss or ask questions!
Bitcoin Optech newsletter #383 is here: - describes a fixed vulnerability affecting the NBitcoin library - summarizes the LNHANCE soft fork proposal - relays a call to action to benchmark Bitcoin script execution under GSR's varops budget - highlights discussion of optimizations to SLH-DSA (SPHINCS) post-quantum signatures - Optech Newsletter #383 Podcast Bruno Garcia posted to Delving Bitcoin about a theoretical consensus failure in NBitcoin that could occur when using OP_NIP... Moonsettler proposes a soft fork for LNHANCE now that all four of its constituent opcodes have updated BIPs and reference implementations... Julian posted a call to action to benchmark Bitcoin script execution under the varops budget... Continuing the discussions around hardening Bitcoin against quantum computing, conduition presented his work on optimizing the SPHINCS signing algorithm... Bitcoin Optech will host an audio recap discussion of this newsletter on Riverside.fm Tuesday at 17:30 UTC. Join us to discuss or ask questions!
Bitcoin Optech newsletter #382 is here: - provides an update on compact block reconstruction discussions - relays a call to activate BIP3 - summarizes popular Q&A from Stack Exchange - Optech Newsletter #382 Podcast 0xB10C posted an update to Delving Bitcoin about his statistics around compact block reconstruction... Murch posted to the Bitcoin-Dev mailing list a formal motion to activate BIP3... Selected Q&A from Bitcoin Stack Exchange: - Do pruned nodes store witness inscriptions? - Increasing probability of block hash collisions when difficulty is too high - What is the purpose of the initial 0x04 byte in all extended public and private keys? Bitcoin Optech will host an audio recap discussion of this newsletter on Riverside.fm Tuesday at 17:30 UTC. Join us to discuss or ask questions!
Bitcoin Optech newsletter #381 is here: - looks at an analysis of how block propagation times may affect miner revenue - describes a new approach for resolving protocols where multiple parties share funds - summarizes changes to services/client software - Optech Newsletter #381 Podcast Antoine Poinsot posted to Delving Bitcoin about modeling stale block rates and how block propagation time affects a miner’s revenue as a function of its hashrate... ZmnSCPxj posted to Delving Bitcoin about private key handover, an optimization that protocols can implement when funds, previously owned by two parties, need to be refunded to a single entity... Changes to services and client software: - Arkade launches - Mempool monitoring mobile application - Web-based policy and miniscript IDE - Phoenix Wallet adds taproot channels - Nunchuk 2.0 launches - LN gossip traffic analysis tool announced 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!
Bitcoin Optech newsletter #379 is here: - shares an analysis comparing the historical performance of the OpenSSL and libsecp256k1 libraries - highlights multiple discussions about restricting data - summarizes a proposed post-quantum signature aggregation opcode - summarizes an idea for STARK proof verification in Bitcoin Script - updates progress on BIP54's consensus cleanup - Optech Newsletter #379 Podcast Sebastian Falbesoner posted to Delving about comparing the performance of ECDSA signature validation between OpenSSL and libsecp256k1 over the last decade... Multiple conversations examined ideas to change the limits of various fields in consensus... Tadge Dryja posted to the Bitcoin-Dev mailing list a proposal for an OP_CHECKINPUTVERIFY (OP_CIV) opcode that enables a locking script to commit to a specific UTXO being spent in the same transaction... Abdelhamid Bakhta posted to Delving Bitcoin a detailed proposal for a new tapscript opcode OP_STARK_VERIFY which would enable the verification of a specific variant of STARK proof in Bitcoin Script... Antoine Poinsot posted to the Bitcoin-Dev mailing list an update on his consensus cleanup work on BIP54... 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!
Bitcoin Optech newsletter #378 is here: - announces four vulnerabilities affecting older versions of the Bitcoin Core full node - summarizes popular Q&A from Stack Exchange - Optech Newsletter #378 Podcast Antoine Poinsot recently posted to the Bitcoin-Dev mailing list four Bitcoin Core security advisories for low-severity vulnerabilities that were fixed in Bitcoin Core 30.0... Selected Q&A from Bitcoin Stack Exchange: - Why was -datacarriersize redefined in 2022, and why was the 2023 proposal to expand it not merged? - What is the smallest valid transaction that can be included in a block? - Why does Bitcoin Core continue to give witness data a discount even when it is used for inscriptions? - The ever-growing Bitcoin blockchain size? - I read that OP_TEMPLATEHASH is a variant of OP_CTV. How do they differ? 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!
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Bitcoin Optech 2 months ago
Sindura Saraswathi, ZmnSCPxj and Eugene Siegel joined Optech to discuss Newsletter #375: - Optimal Threshold Signatures - Flattening certain nested threshold signatures - Theoretical limitations on embedding data in the UTXO set - The ‘Compact block harness’ Bitcoin Core PR Review Club - And more You can listen on our website: Fountain: Spotify:
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Bitcoin Optech 2 months ago
Bitcoin Optech newsletter #376 is here: - shares an update on the proposal for nodes to share their current block template - summarizes a paper outlining a covenant-less vault construction - Bitcoin Core 30.0 release - Optech Newsletter #376 Podcast Discussion continued around the proposal for full node peers to occasionally send each other their current template for the next block using compact block relay encoding... Francesco Madonna posted to Delving Bitcoin about a concept which is a covenant-less vault model using taproot, OP_CHECKSEQUENCEVERIFY, and OP_CHECKLOCKTIMEVERIFY... Bitcoin Core 30.0 is the latest version release of the network’s predominant full node. Its release notes describe several significant improvements... 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!
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Bitcoin Optech 2 months ago
Bitcoin Optech newsletter #375 is here: - describes research into tradeoffs between usability and security in threshold signatures - summarizes an approach to convert nested threshold signatures into a single-layer signing group - examines the extent to which data could be embedded in the UTXO set under a restrictive set of rules - recaps the "Compact block harness" PR Review Meeting - Optech Newsletter #375 Podcast Sindura Saraswathi posted research, co-authored by her and Korok Ray, to Delving Bitcoin about determining the optimal threshold for a multisignature scheme... ZmnSCPxj posted to Delving Bitcoin to describe how to avoid using nested schnorr signatures in some cases that have not been proven safe... Adam “Waxwing” Gibson started a discussion on the mailing list about the extent to which data could be embedded in the UTXO set under a restrictive set of rules for Bitcoin transactions... 'Compact block harness' is a PR by Crypt-iQ that increases the fuzz test coverage by adding a test harness for the compact block relay logic... 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!