Bitcoin Optech Podcast

Mark “Murch” Erhardt and Mike Schmidt are joined by Antoine Poinsot, Peter Todd, Josh Doman, and TheCharlatan to discuss ⁠Newsletter #358⁠.News● Calculating the selfish mining danger threshold (0:52) ● Relay censorship resistance through top mempool set reconciliation (59:26) ● Updating BIP390 to allow duplicate participant keys in `musig()` expressions (55:50) ● Descriptor encryption library (31:35) Bitcoin Core PR Review Club● Separate UTXO set access from validation functions (43:05) Releases and release candidates● Core Lightning 25.05rc1 (58:25) ● LND 0.19.1-beta (58:38) Notable code and documentation changes● Bitcoin Core #32406 (19:54) ● LDK #3793 (1:14:21) ● LDK #3792 (1:14:59) ● LND #9127 (1:18:38) ● LND #9858 (1:20:04) ● BOLTs #1243 (1:21:49)

Mark “Murch” Erhardt and Mike Schmidt are joined by Jose SK, Clara Shikhelman, Vojtěch Strnad, Robin Linus, and Dan Gould to discuss ⁠Newsletter #357⁠.News● Syncing full nodes without witnesses (1:30) Changing consensus● Quantum computing report (17:38) ● Transaction weight limit with exception to prevent confiscation (41:49) ● Removing outputs from the UTXO set based on value and time (53:47) Releases and release candidates● Core Lightning 25.05rc1 (1:07:45) ● LND 0.19.1-beta.rc1 (1:08:02) Notable code and documentation changes● Bitcoin Core #32582 (1:09:08) ● Bitcoin Core #31375 (1:07:45) ● BIPs #1483 (1:14:16)

Mark “Murch” Erhardt and Mike Schmidt are joined by Carla Kirk-Cohen, Joost Jager, and Elias Rohrer to discuss Newsletter #356.News● Do attributable failures reduce LN privacy? (0:57) Selected Q&A from Bitcoin Stack Exchange● Which transactions get into blockreconstructionextratxn? (40:40) ● Why would anyone use OP_RETURN over inscriptions, aside from fees? (46:47) ● Why is my Bitcoin node not receiving incoming connections? (48:25) ● How do I configure my node to filter out transactions larger than 400 bytes? (49:44) ● What does not publicly routable node in Bitcoin Core P2P mean? (52:21) ● Why would a node would ever relay a transaction? (52:46) ● Is selfish mining still an option with compact blocks and FIBRE? (55:00) Releases and release candidates● Core Lightning 25.05rc1 (57:25) ● LDK 0.1.3 (57:56) Notable code and documentation changes● Bitcoin Core #31622 (1:00:32) ● Eclair #3065 (37:15) ● LDK #3796 (1:03:04) ● BIPs #1760 (1:03:40) ● BIPs #1850 (1:06:13) ● BIPs #1793 (1:09:05)

Dave Harding is joined by Alex Myers and Rodolfo Novak to discuss Newsletter #355.Changes to services and client software● Cake Wallet added payjoin v2 support (2:38) ● Sparrow adds pay-to-anchor features (6:37) ● Safe Wallet 1.3.0 released (8:00) ● COLDCARD Q v1.3.2 released (9:15) ● Transaction batching using payjoin (19:07) ● JoinMarket Fidelity Bond Simulator (20:46) ● Bitcoin opcodes documented (26:39) ● Bitkey code open sourced (27:59) Releases and release candidates● LND 0.19.0-beta (33:43) ● Core Lightning 25.05rc1 (40:12) Notable code and documentation changes● Bitcoin Core #32423 (46:47) ● Bitcoin Core #31444 (49:51) ● Core Lightning #8140 (52:08) ● Core Lightning #8136 (54:16) ● Core Lightning #8266 (55:52) ● Core Lightning #8021 (58:38) ● Core Lightning #8226 (1:01:29) ● LND #9801 (1:02:54)

Mark “Murch” Erhardt and Mike Schmidt are joined by Eugene Siegel, Chris Stewart, Bram Cohen, and Robin Linus to discuss Newsletter #353.News● Vulnerability disclosure affecting old versions of Bitcoin Core (1:17) Changing consensus● Proposed BIP for 64-bit arithmetic in Script (5:28) ● Proposed opcodes for enabling recursive covenants through quines (23:11) ● Description of benefits to BitVM from `OP_CTV` and `OP_CSFS` (36:39) Releases and release candidates● LND 0.19.0-beta.rc4 (1:07:28) Notable code and documentation changes● Bitcoin Core #32155 (1:08:27) ● Bitcoin Core #28710 (1:09:38) ● Core Lightning #8272 (1:13:28) ● LND #8330 (1:14:09) ● Rust Bitcoin #4458 (1:14:52) ● BIPs #1848 (1:04:33) ● BIPs #1841 (1:16:25) ● BIPs #1821 (1:16:42)

Mark “Murch” Erhardt and Mike Schmidt are joined by Ruben Somsen, Salvatore Ingala, and Stéphan Vuylsteke to discuss Newsletter #353.News● BIP30 consensus failure vulnerability (0:52) ● Avoiding BIP32 path reuse (28:33) Bitcoin Core PR Review Club● Add bitcoin wrapper executable (16:38) Releases and release candidates● LND 0.19.0-beta.rc4 (45:01) Notable code and documentation changes● Core Lightning #8227 (45:18) ● Core Lightning #8162 (46:43) ● Core Lightning #8166 (47:44) ● Core Lightning #8237 (48:49) ● LDK #3700 (49:28) ● Rust Bitcoin #4387 (49:55) ● BIPs #1835 (50:15) ● BIPs #1800 (55:03) ● BOLTs #1245 (56:37)

Mark “Murch” Erhardt and Sjors Provoost discuss Newsletter #352.News● Comparison of cluster linearization techniques (0:41) ● Increasing or removing Bitcoin Core's `OP_RETURN` size limit (6:46) Releases and release candidates● LND 0.19.0-beta.rc3 (1:01:16) Notable code and documentation changes● Bitcoin Core #31250 (1:02:10) ● Eclair #3064 (1:06:02) ● BTCPay Server #6684 (1:07:46) ● BIPs #1555 (1:10:34)

Mark “Murch” Erhardt and Mike Schmidt are joined by Jonas Nick and Salvatore Ingala to discuss Newsletter #351.News● Interactive aggregate signatures compatible with secp256k1 (0:50) ● Standardized backup for wallet descriptors (21:34) Selected Q&A from Bitcoin Stack Exchange● Practicality of half-aggregated schnorr signatures? (17:16) ● What's the largest size OP_RETURN payload ever created? (41:17) ● Non-LN explanation of pay-to-anchor? (43:29) ● Up-to-date statistics about chain reorganizations? (48:08) ● Are Lightning channels always P2WSH? (52:33) ● Child-pays-for-parent as a defense against a double spend? (53:40) ● What values does CHECKTEMPLATEVERIFY hash? (59:06) ● Why can't Lightning nodes opt to reveal channel balances for better routing efficiency? (59:32) ● Does post-quantum require hard fork or soft fork? (1:02:27) Releases and release candidates● LND 0.19.0-beta.rc3 (1:07:39) Notable code and documentation changes● Bitcoin Core #31247 (1:07:58) ● LDK #3601 (1:10:14)

Mark “Murch” Erhardt and Mike Schmidt are joined by Niklas Gögge to discuss ⁠Newsletter #350⁠.Changes to services and client software● Bitcoin Knots version 28.1.knots20250305 released (11:26) ● PSBTv2 explorer announced (13:51) ● LNbits v1.0.0 released (14:38) ● The Mempool Open Source Project® v3.2.0 released (15:22) ● Coinbase MPC library released (17:25) ● Lightning Network liquidity tool released (21:20) ● Versioned Storage Service announced (22:25) ● Fuzz testing tool for Bitcoin nodes (1:17) ● Bitcoin Control Board components open-sourced (23:50) Releases and release candidates● Bitcoin Core 29.0 (25:13) ● LND 0.19.0-beta.rc2 (34:41) Notable code and documentation changes● LDK #3593 (35:04) ● BOLTs #1242 (35:57) Correction (37:38)

Mark “Murch” Erhardt and Dave Harding are joined by Sebastian Falbesoner, Ruben Somsen, and Abubakar Sadiq Ismail to discuss ⁠Newsletter #349⁠.News● SwiftSync speedup for initial block download (0:34) Bitcoin Core PR Review Club● Add Fee rate Forecaster Manager (29:33) Releases and release candidates● Core Lightning 25.02.1 (46:54) ● Core Lightning 24.11.2 (47:03) ● BTCPay Server 2.1.0 (48:14) ● Bitcoin Core 29.0rc3 (49:25) ● LND 0.19.0-beta.rc2 (51:21) Notable code and documentation changes● LDK #2256 (53:52) ● LND #9669 (56:16) ● Rust Bitcoin #4302 (57:24)

Mark “Murch” Erhardt and Mike Schmidt are joined by Jonas Nick, Jameson Lopp, Steven Roose, Gregory Sanders, and Salvatore Ingala to discuss ⁠Newsletter #348⁠.News● Educational and experimental-based secp256k1 implementation (1:09) Changing consensus● Should vulnerable bitcoins be destroyed? (9:17) ● Securely proving UTXO ownership by revealing a SHA256 preimage (34:52) ● Draft BIP for destroying quantum-insecure bitcoins (44:01) ● Criticism of CTV motivation (51:16) ● CTV+CSFS benefits (1:06:02) ● Benefit of CTV to Ark users (1:24:37) ● OP_CHECKCONTRACTVERIFY semantics (1:31:49) ● Draft BIP published for consensus cleanup (1:58:29) Releases and release candidates● BDK wallet 1.2.0 (2:06:03) ● LDK v0.1.2 (2:06:48) ● Bitcoin Core 29.0rc3 (2:07:13) ● LND 0.19.0-beta.rc1 (2:08:36) Notable code and documentation changes● Bitcoin Core #31363 (2:09:03) ● Bitcoin Core #31278 (2:09:44) ● Eclair #3050 (2:12:41) ● Eclair #2963 (2:13:54) ● Eclair #3045 (2:14:44) ● LDK #3670 (2:15:47) ● LND #9620 (2:16:24)

Mark “Murch” Erhardt and Mike Schmidt are joined by Sjors Provoost and Antoine Poinsot to discuss ⁠Newsletter #347⁠.News● LN upfront and hold fees using burnable outputs (0:54) ● Discussion of testnets 3 and 4 (5:11) ● Plan to relay certain taproot annexes (19:01) Selected Q&A from Bitcoin Stack Exchange● Why is the witness commitment optional? (24:58) ● Can all consensus valid 64 byte transactions be (third party) malleated to change their size? (36:39) ● How long does it take for a transaction to propagate through the network? (47:37) ● Utility of longterm fee estimation (49:31) ● Why are two anchor outputs are used in the LN? (54:34) ● Why are there no BIPs in the 2xx range? (57:19) ● Why doesn't Bech32 use the character b? (59:55) ● Bech32 error detection and correction reference implementation (1:00:23) ● How to safely spend/burn dust? (1:02:48) ● How is the refund transaction in Asymmetric Revocable Commitments constructed? (1:07:34) ● Which applications use ZMQ with Bitcoin Core? (42:15) Releases and release candidates● Bitcoin Core 29.0rc2 (1:08:21) ● LND 0.19.0-beta.rc1 (1:08:55) Notable code and documentation changes● Bitcoin Core #31603 (45:12) ● Eclair #3044 (1:09:45) ● Eclair #3026 (1:10:38) ● LDK #3649 (1:11:02) ● LDK #3665 (1:11:59) ● LND #8453 (1:14:28) ● BIPs #1792 (1:16:00) ● BIPs #1782 (1:16:40)

Mark “Murch” Erhardt and Mike Schmidt are joined by Matt Morehouse, Yong Yu, Alejandro De La Torre, Jan B, and Marco De Leon to discuss ⁠Newsletter #346⁠.News● Discussion of LND's dynamic feerate adjustment system (1:24) Changes to services and client software● Wally 1.4.0 released (17:17) ● Bitcoin Core Config Generator announced (18:05) ● A regtest development environment container (18:55) ● Explora transaction visualization tool (20:17) ● Hashpool v0.1 tagged (21:35) ● DMND launching pooled mining (24:36) ● Krux adds taproot and miniscript (22:21) ● Source-available secure element announced (23:01) ● Nunchuk launches Group Wallet (45:04) ● FROSTR protocol announced (46:03) ● Bark launches on signet (46:57) ● Cove Bitcoin wallet announced (48:43) Releases and release candidates● Bitcoin Core 29.0rc2 (50:38) Notable code and documentation changes● Bitcoin Core #31649 (1:03:19) ● Bitcoin Core #31283 (37:27) ● Eclair #3037 (1:15:29) ● LND #9546 (1:16:33) ● LND #9458 (1:17:17) ● BTCPay Server #6581 (1:18:10) ● BDK #1839 (1:20:59) ● BOLTs #1233 (15:39)

Mark “Murch” Erhardt and Mike Schmidt are joined by Sindura Saraswathi, Christian Kümmerle, and Stéphan Vuylsteke to discuss Newsletter #345.News● P2P traffic analysis (1:35) ● Research into single-path LN pathfinding (6:45) ● Probabilistic payments using different hash functions as an xor function (21:17) Bitcoin Core PR Review Club● Stricter internal handling of invalid blocks (26:12) Releases and release candidates● Eclair v0.12.0 (37:49) Notable code and documentation changes● Bitcoin Core #31407 (38:52) ● Eclair #3027 (43:22) ● Eclair #3007 (44:17) ● Eclair #2976 (44:57) ● LDK #3608 (47:17) ● LDK #3624 (48:12) ● LDK #3016 (50:28) ● LDK #3629 (52:15) ● BDK #1838 (53:06)

Mark “Murch” Erhardt and Mike Schmidt are joined by Matt Morehouse, Matt Corallo, and Hunter Beast to discuss Newsletter #344.News● Disclosure of fixed LND vulnerability allowing theft (0:57) ● Discussion about Bitcoin Core's priorities (10:49) Changing consensus● Bitcoin Forking Guide (1:01:11) ● Update on BIP360 pay-to-quantum-resistant-hash (P2QRH) (34:37) ● Private block template marketplace to prevent centralizing MEV (21:06) Releases and release candidates● Core Lightning 25.02 (1:09:57) Notable code and documentation changes● Eclair #3019 (1:11:21) ● Eclair #3016 (1:12:05) ● LDK #3342 (33:13) ● Rust Bitcoin #4114 (1:12:50) ● Rust Bitcoin #4111 (1:14:29) ● BIPs #1758 (1:15:09) ● BIPs #1750 (1:17:07) ● BIPs #1712 (1:18:10)

Dave Harding and Mike Schmidt discuss Newsletter #343.

Dave Harding and Mike Schmidt are joined by Bastien Teinturier and Joost Jager discuss ⁠Newsletter #342⁠.News● Allowing mobile wallets to settle channels without extra UTXOs (0:59) ● Continued discussion about an LN quality of service flag (13:14) Changes to services and client software● Ark Wallet SDK released (40:28) ● Zaprite adds BTCPay Server support (40:57) ● Iris Wallet desktop released (41:21) ● Sparrow 2.1.0 released (41:41) ● Scure-btc-signer 1.6.0 released (42:38) ● Py-bitcoinkernel alpha (43:48) ● Rust-bitcoinkernel library (44:30) ● BIP32 cbip32 library (45:56) ● Lightning Loop moves to MuSig2 (46:22) Notable code and documentation changes● Bitcoin Core #27432 (47:01) ● Bitcoin Core #30529 (48:29) ● Bitcoin Core #31384 (49:42) ● Core Lightning #8059 (50:52) ● Core Lightning #7985 (53:41) ● Core Lightning #7887 (54:32) ● Eclair #2967 (26:06) ● Eclair #2979 (32:24) ● Eclair #3002 (34:32) ● LDK #3575 (57:35) ● LDK #3562 (23:51) ● BOLTs #1205 (26:13)

Mark “Murch” Erhardt and Mike Schmidt discuss Newsletter #341.News● Continued discussion about probabilistic payments (0:34) ● Continued discussion about ephemeral anchor scripts for LN (7:26) ● Stats on orphan evictions (14:31) ● Updated proposal for updated BIP process (27:08) Bitcoin Core PR Review Club● Cluster mempool: introduce TxGraph (35:43) Releases and release candidates● LND v0.18.5-beta (43:48) ● Bitcoin Inquisition 28.1 (44:10) Notable code and documentation changes● Bitcoin Core #25832 (51:43) ● Eclair #2989 (55:49) ● LDK #3440 (56:36) ● LND #9470 (57:14) ● BTCPay Server #6580 (58:15)

Mark “Murch” Erhardt and Mike Schmidt are joined by Matt Morehouse, Johan Halseth, Pieter Wuille, Sergi Delgado, Bastien Teinturier, Oleksandr Kurbatov, Antoine Poinsot and Bob McElrath to discuss Newsletter #340.News● Channel force closure vulnerability in LDK (2:14) ● Zero-knowledge gossip for LN channel announcements (16:01) ● Discovery of previous research for finding optimal cluster linearization (26:29) ● Erlay update (46:38) ● Tradeoffs in LN ephemeral anchor scripts (1:09:50) ● Emulating OP_RAND (1:30:30) ● Discussion about lowering the minimum transaction relay feerate (1:36:33) Changing consensus● Updates to cleanup soft fork proposal (1:43:46) ● Request for a covenant design supporting Braidpool (2:28:59) ● Deterministic transaction selection from a committed mempool (2:04:52) ● Fast difficulty adjustment algorithm for a DAG blockchain (2:19:24) Releases and release candidates● BDK Wallet 1.1.0 (2:39:15) ● LND v0.18.5-beta.rc1 (2:39:43) Notable code and documentation changes● Bitcoin Core #21590 (38:58) ● Eclair #2983 (1:23:30) ● Eclair #2968 (1:27:53) ● LDK #3556 (2:40:31) ● LND #9456 (2:41:10)

Mark “Murch” Erhardt and Dave Harding are joined by Matt Morehouse and 0xB10C to discuss Newsletter #339.News● Vulnerability in LDK claim processing (0:47)● Replacement cycling attacks with miner exploitation (17:28)● Updated stats on compact block reconstruction (23:56)Selected Q&A from Bitcoin Stack Exchange● Who uses or wants to use PSBTv2 (BIP370)? (32:38)● In the bitcoin's block genesis, which parts can be filled arbitrarily? (34:41)● Lightning force close detection (36:47)● Is a segwit-formatted transaction with all inputs of non-witness program type valid? (40:01)● P2TR Security Question (41:41)● What exactly is being done today to make Bitcoin quantum-safe? (44:27)● What are the harmful effects of a shorter inter-block time? (47:57)● Could proof-of-work be used to replace policy rules? (51:19)● How does MuSig work in real Bitcoin scenarios? (54:54)● How does the -blocksxor switch that obfuscates the blocks.dat files work? (57:18)● How does the related key attack on Schnorr signatures work? (59:42)Releases and release candidates● LDK v0.1.1 (1:01:19)Notable code and documentation changes● Bitcoin Core #31376 (1:03:24)● Bitcoin Core #31583 (1:04:48)● Bitcoin Core #31590 (1:05:40)● Eclair #2982 (1:07:17)● BDK #1614 (1:11:39)● BOLTs #1110 (1:12:08)

Mark “Murch” Erhardt and Mike Schmidt are joined by Andrew Toth and Dave Harding to discuss ⁠Newsletter #338⁠. News - Draft BIP for unspendable keys in descriptors (0:49) - PSBTv2 integration testing (9:55) - Correction about offchain DLCs (15:25) Changes to services and client software - Bull Bitcoin Mobile Wallet adds payjoin (28:10) - Bitcoin Keeper adds miniscript support (28:52) - Nunchuk adds taproot MuSig2 features (29:26) - Jade Plus signing device announced (32:08) - Coinswap v0.1.0 released (32:36) - Bitcoin Safe 1.0.0 released (35:14) - Bitcoin Core 28.0 policy demonstration (35:41) - Rust-payjoin 0.21.0 released (36:21) - PeerSwap v4.0rc1 (37:34) - Joinpool prototype using CTV (38:24) - Rust joinstr library announced (39:58) - Strata bridge announced (40:36) Releases and release candidates - BTCPay Server 2.0.6 (41:41) Notable code and documentation changes - Bitcoin Core #31397 (42:19) - Eclair #2896 (44:21) - LDK #3408 (46:02) - LND #9405 (47:57)

Mark “Murch” Erhardt and Mike Schmidt are joined by vnprc to discuss ⁠⁠Newsletter #337⁠⁠. News - Continued discussion about rewarding pool miners with tradeable ecash shares (0:35) - Offchain DLCs (38:32) Releases and release candidates - LDK v0.1 (39:34) Notable code and documentation changes - Eclair #2936 (41:32) - Rust Bitcoin #3792 (42:46) - BDK #1789 (43:42) - BIPs #1687 (46:39) - BIPs #1396 (50:15)

Mark “Murch” Erhardt and Mike Schmidt are joined by Abubakar Sadiq Ismail, Gregory Sanders, and Daniel Roberts to discuss ⁠Newsletter #336⁠. News Investigating mining pool behavior before fixing a Bitcoin Core bug (1:07) Contract-level relative timelocks (15:04) Multiparty LN-Symmetry variant with penalties for limiting published updates (29:06) Releases and release candidates Bitcoin Core 28.1 (39:54) BDK 0.30.1 (40:45) LDK v0.1.0-beta1 (42:01) Notable code and documentation changes Bitcoin Core #28121 (42:22) BDK #1592 (43:14)

Dave Harding and Mike Schmidt are joined by Yuval Kogman, Jeremy Rubin, and Steve Myers to discuss ⁠Newsletter #335⁠. News Deanonymization attacks against centralized coinjoin (1:39) Updated ChillDKG draft (14:09) Changing consensus CTV enhancement opcodes (18:41) Adjusting difficulty beyond 256 bits (31:52) Transitory soft forks for cleanup soft forks (33:44) Quantum computer upgrade path (48:09) Consensus cleanup timewarp grace period (56:10) Releases and release candidates BDK wallet-1.0.0 (1:06:44) LND 0.18.4-beta (1:17:28) Core Lightning v24.11.1 (1:18:13) Bitcoin Core 28.1rc2 (1:18:47) LDK v0.1.0-beta1 (1:19:37) Notable code and documentation changes Bitcoin Core #31223 (1:20:19) Eclair #2888 (1:21:09) LDK #3495 (1:22:35) LDK #3436 (1:24:31) LDK #3435 (1:25:02) LDK #3365 (1:26:04) LDK #3340 (1:26:41) BDK #1670 (1:28:47) BIPs #1689 (1:31:45) BIPs #1697 (1:33:49) BLIPs #52 (1:34:21) BLIPs #54 (1:35:40)

Mark “Murch” Erhardt and Mike Schmidt are joined by Dave Harding, Niklas Gögge, Gloria Zhao, and Rearden to discuss ⁠Newsletter #334: 2024 Year-in-Review Special⁠. January Fee-dependent timelocks (16:18) Optimized contract protocol exits (17:20) LN-Symmetry proof-of-concept implementation (18:22) February Replace by feerate (22:32) Human-readable payment instructions (27:25) Improved ASMap generation (28:09) LN dual funding (32:33) Trustless betting on future feerates (32:56) Summary 2024: Vulnerability disclosures (7:05) March BINANAs and BIPs (33:33) Enhanced feerate estimation (34:41) More efficient transaction sponsorship (46:08) April Consensus cleanup (50:06) Reforming the BIPs process (51:08) Inbound routing fees (53:10) Weak blocks (54:01) Restarting testnet (57:43) Developers arrested (1:00:06) Summary 2024: Cluster mempool (1:01:10) May Silent payments (1:06:51) BitVMX (1:07:37) Anonymous usage tokens (1:09:50) LN channel upgrades (1:12:00) Ecash for pool miners (1:13:33) Miniscript specification (1:14:54) Utreexo beta (1:16:16) June LN payment feasibility and channel depletion (1:18:17) Quantum-resistant transaction signing (1:20:02) Summary 2024: P2P transaction relay (1:20:39) July Blinded paths for BOLT11 invoices (1:31:07) ChillDKG key generation for threshold signatures (1:31:47) BIPs for MuSig and threshold signatures (1:32:18) August Hyperion network simulator (1:33:00) Full RBF (1:33:56) Summary 2024: Covenants and script upgrades (2:08) September Hybrid jamming mitigation tests and tweaks (1:35:10) Shielded CSV (1:38:40) LN offline payments (1:41:22) October BOLT12 offers (1:42:34) Mining interfaces, block withholding, and share validation cost (1:43:13) Summary 2024: Major releases of popular infrastructure projects (1:50:41) November SuperScalar timeout tree channel factories (1:51:19) Fast and cheap low-value offchain payment resolution (1:53:29) Summary 2024: Bitcoin Optech (1:55:17)

Mark “Murch” Erhardt and Mike Schmidt are joined by Dave Harding, /dev/fd0, and Gloria Zhao to discuss Newsletter #333. News Vulnerability allowing theft from LN channels with miner assistance (1:11) Deanonymization vulnerability affecting Wasabi and related software (12:00) Insights into channel depletion (18:12) Poll of opinions about covenant proposals (31:14) Incentive-based pseudo-covenants (41:49) Bitcoin Core developer meeting summaries (46:45) Bitcoin Core PR Review Club Track and use all potential peers for orphan resolution (48:18) Changes to services and client software Java-based HWI released (1:00:32) Saving Satoshi Bitcoin development education game announced (1:01:24) Neovim Bitcoin Script plugin (1:02:19) Proton Wallet adds RBF (1:03:36) Selected Q&A from Bitcoin Stack Exchange How long does Bitcoin Core store forked chains? (1:03:51) What is the point of solo mining pools? (1:05:02) Is there a point to using P2TR over P2WSH if I only want to use the script path? (1:11:17) Releases and release candidates Core Lightning 24.11 (1:13:23) BTCPay Server 2.0.4 (1:16:59) LND 0.18.4-beta.rc2 (1:17:23) Bitcoin Core 28.1RC1 (1:17:44) BDK 1.0.0-beta.6 (1:18:36) Notable code and documentation changes Bitcoin Core #31096 (1:18:58) Bitcoin Core #31175 (1:19:51) Bitcoin Core #31112 (1:21:37) LDK #3446 (1:22:56) Rust Bitcoin #3682 (1:26:13) BTCPay Server #5743 (1:27:17) BDK #1756 (1:30:23) BIPs #1535 (1:31:12) BOLTs #1180 (1:32:33)

Dave Harding and Mike Schmidt are joined by René Pickhardt and Christian Decker to discuss Pickhardt's ⁠Lightning Network channel depletion research⁠. Summary of Pickhardt's research (1:01) Why look at wealth distributions? (5:45) What can be learned from depletion? (11:38) Circular rebalancing (13:33) What determines where the spanning tree is? (15:28) Mitigating depletion (20:14) Adjacent channels and their impact (26:39) Multiparty channels, channel factories, and Ark (29:52) Hub-and-spoke topology discussion (41:06) What real world data would inform the theoretical? (54:54)

Mark “Murch” Erhardt and Mike Schmidt are joined by Antoine Riard and Antoine Poinsot to discuss ⁠Newsletter #332⁠. News Transaction censorship vulnerability (0:55) Continued discussion about consensus cleanup soft fork proposal (19:20) Releases and release candidates Eclair v0.11.0 (46:45) LDK v0.0.125 (47:26) Core Lightning 24.11rc3 (47:59) LND 0.18.4-beta.rc1 (48:21) Bitcoin Core 28.1RC1 (48:34) Notable code and documentation changes Bitcoin Core #30708 (49:15) Core Lightning #7832 (50:32) LND #8270 (51:36) LND #8390 (52:49) BIPs #1534 (55:49)

Mark “Murch” Erhardt and Mike Schmidt are joined by Anthony Towns to discuss ⁠Newsletter #331⁠. News Lisp dialect for Bitcoin scripting (0:48) Selected Q&A from Bitcoin Stack Exchange How does ColliderScript improve Bitcoin and what features does it enable? (43:24) Why do standardness rules limit transaction weight? (48:10) Is the scriptSig spending an PayToAnchor output expected to always be empty? (56:16) What happens to the unused P2A outputs? (57:13) Why doesn't Bitcoin's PoW algorithm use a chain of lower-difficulty hashes? (1:01:47) Clarification on false value in Script (1:04:38) What is this strange microtransaction in my wallet? (1:06:02) Are there any UTXOs that can not be spent? (1:09:04) Why was BIP34 not implemented via the coinbase tx's locktime or nSequence? (1:13:15) Releases and release candidates Core Lightning 24.11rc2 (1:15:19) BDK 0.30.0 (1:15:49) LND 0.18.4-beta.rc1 (1:16:16) Notable code and documentation changes Bitcoin Core #31122 (1:17:17) Core Lightning #7852 (1:20:25) Core Lightning #7740 (1:21:27) Core Lightning #7719 (1:22:48) Eclair #2935 (1:23:47) LDK #3137 (1:24:34) LND #8337 (1:26:22)

Mark “Murch” Erhardt and Mike Schmidt are joined by ZmnSCPxj, Vojtěch Strnad, Moonsettler, Brandon Black, Ethan Heilman, and Dusty Daemon to discuss Newsletter #330.

Mark “Murch” Erhardt discusses Newsletter #329. News MAD-based offchain payment resolution (OPR) protocol (0:21) Papers about IP-layer censorship of LN payments (3:10) Releases and release candidates BTCPay Server 2.0.3 (6:21) Notable code and documentation changes Bitcoin Core #30592 (8:29) Bitcoin Core #30930 (9:46) LDK #3283 (11:35) LND #7762 (12:31)

Mark “Murch” Erhardt and Gregory Sanders discuss Newsletter #328. News Disclosure of a vulnerability affecting Bitcoin Core versions before 25.1 (0:53) Bitcoin Core PR Review Club Ephemeral Dust (6:54) Releases and release candidates Bitcoin Core 27.2 (14:55) Libsecp256k1 0.6.0 (15:40) Notable code and documentation changes LDK #3360 (17:40) LDK #3207 (18:45)

Mark “Murch” Erhardt and Mike Schmidt are joined by Andrew Toth to discuss ⁠Newsletter #327⁠. News Timeout tree channel factories (0:50) Draft BIP for DLEQ proofs (10:53) Releases and release candidates BTCPay Server 2.0.0 (20:02) Notable code and documentation changes Bitcoin Core #31130 (22:56) LDK #3007 (25:14) BIPs #1676 (27:15)

Dave Harding and Mike Schmidt are joined by ZmnSCPxj to discuss his SuperScalar proposal. Why a deep dive? (0:40) Proposal overview (1:58) Importance of reallocating liquidity (4:13) What about overloading channels with liquidity from the start? (9:42) Discussion of multi-LSP vs single LSP approaches (13:05) Ensuring unilateral exit is possible (15:22) Malicious users forcing unilateral closes (20:21) Decker–Wattenhofer channels vs John Law's tunable penalties (27:11) Decker–Wattenhofer relative lock times impact on users (38:44) Discussion of trustless non-P2P protocol structure (40:01) Contrasting SuperScalar with Ark (44:08) Implementation discussion (48:44)

Mark “Murch” Erhardt and Mike Schmidt are joined by Elle Mouton and Andrew Toth to discuss Newsletter #326. News Updates to the version 1.75 channel announcements proposal (1:36) Draft BIP for sending silent payments with PSBTs (16:28) Selected Q&A from Bitcoin Stack Exchange Duplicate blocks in blk*.dat files? (30:07) How was the structure of pay-to-anchor decided? (32:45) What are the benefits of decoy packets in BIP324? (36:38) Why is the opcode limit 201? (39:20) Will my node relay a transaction if it is below my minimum tx relay fee? (40:31) Why doesn't the Bitcoin Core wallet support BIP69? (42:09) How can I enable testnet4 when using Bitcoin Core 28.0? (44:50) What are the risks of broadcasting a transaction that reveals a `scriptPubKey` using a low-entropy key? (47:33) Releases and release candidates Core Lightning 24.08.2 (52:12) Notable code and documentation changes Eclair #2925 (52:56) LND #9172 (53:37) Rust Bitcoin #2960 (55:47)

Mark “Murch” Erhardt and Mike Schmidt are joined by Olaoluwa Osuntokun and Steven Roose to discuss ⁠Newsletter #325⁠. News LN Summit 2024 notes (0:51) Changes to services and client software Coinbase adds taproot send support (49:03) Dana wallet released (51:53) Kyoto BIP157/158 light client released (53:20) DLC Markets launches on mainnet (1:01:39) Ashigaru wallet announced (1:02:30) DATUM protocol announced (1:03:10) Bark Ark implementation announced (1:03:55) Phoenix v2.4.0 and phoenixd v0.4.0 released (1:11:31) Releases and release candidates BDK 1.0.0-beta.5 (1:12:33) Notable code and documentation changes Bitcoin Core #30955 (1:13:11) Eclair #2927 (1:14:37) Eclair #2922 (1:15:38) LDK #3235 (1:16:30) LND #8183 (1:17:21) Rust Bitcoin #3450 (1:18:09)

Mark “Murch” Erhardt and Mike Schmidt are joined by Antoine Poinsot to discuss ⁠Newsletter #324⁠. News Disclosure of vulnerabilities affecting Bitcoin Core versions before 25.0 (1:09) CVE-2024-38365 btcd consensus failure (11:22) Guide for wallets employing Bitcoin Core 28.0 (23:27) Bitcoin Core PR Review Club Add getorphantxs (27:43) Releases and release candidates Bitcoin Inquisition 28.0 (26:35) BDK 1.0.0-beta.5 (31:39) Notable code and documentation changes Core Lightning #7494 (32:22) Core Lightning #7539 (34:46) LDK #3179 (35:46) LND #8960 (36:56) Libsecp256k1 #1479 (37:38) Rust Bitcoin #2945 (39:29) BIPs #1674 (39:49)

Mark “Murch” Erhardt and Mike Schmidt are joined by Bastien Teinturier to discuss ⁠Newsletter #323⁠. News Impending btcd security disclosure (0:54) Releases and release candidates Bitcoin Core 28.0 (3:11) BDK 1.0.0-beta.5 (15:13) Notable code and documentation changes Bitcoin Core #30043 (20:47) Bitcoin Core #30510 (22:15) Core Lightning #7644 (25:06) Eclair #2848 (26:28) Eclair #2860 (30:57) Eclair #2861 (29:17) Eclair #2875 (31:19) LDK #3303 (40:24) BDK #1616 (41:29) BIPs #1600 (46:02) BOLTs #798 (48:25)

Jon Atack and Mike Schmidt are joined by Gloria Zhao and Jonas Nick to discuss ⁠Newsletter #322⁠. News Disclosure of vulnerability affecting Bitcoin Core versions before 24.0.1 (2:01) Hybrid jamming mitigation testing and changes (17:51) Shielded client-side validation (CSV) (25:28) Draft of updated BIP process (48:47) Selected Q&A from Bitcoin Stack Exchange What specific verifications are done on a fresh Bitcoin TX and in what order? (54:31) Why is my bitcoin directory larger than my pruning data limit setting? (55:42) What do I need to have set up to have `getblocktemplate` work? (58:19) Can a silent payment address body be brute forced? (1:00:02) Why does a tx fail `testmempoolaccept` BIP125 replacement but is accepted by `submitpackage`? (1:01:38) How does the ban score algorithm calculate a ban score for a peer? (1:03:53) Releases and release candidates BDK 1.0.0-beta.4 (1:06:41) Bitcoin Core 28.0rc2 (1:06:57) Notable code and documentation changes Eclair #2909 (1:10:15) LND #9095 (1:11:12) LND #8044 (1:11:55)

Rijndael and Mike Schmidt are joined by Andy Schroder and Virtu to discuss ⁠Newsletter #321⁠. News Proving UTXO set inclusion in zero knowledge (1:47) LN offline payments (11:32) DNS seeding for non-IP addresses (30:00) Changes to services and client software Strike adds BOLT12 support (42:15) BitBox02 adds silent payment support (43:29) The Mempool Open Source Project v3.0.0 released (45:22) ZEUS v0.9.0 released (46:39) Live Wallet adds consolidation support (47:04) Bisq adds Lightning support (48:30) Releases and release candidates HWI 3.1.0 (49:32) Core Lightning 24.08.1 (49:56) BDK 1.0.0-beta.4 (50:27) Bitcoin Core 28.0rc2 (51:04) Notable code and documentation changes Bitcoin Core #28358 (52:23) Bitcoin Core #30286 (53:53) Bitcoin Core #30807 (55:24) LND #8981 (56:36) LDK #3140 (57:34) LDK #3163 (58:50) LDK #3010 (59:40) BDK #1581 (1:00:18) BDK #1561 (1:01:21)

Mark “Murch” Erhardt and Mike Schmidt are joined by Bruno Garcia, Shehzan Maredia, Gloria Zhao, Fabian Jahr, and Gregory Sanders to discuss ⁠Newsletter #320⁠. News Mutation testing for Bitcoin Core (1:39) DLC-based loan contract execution (9:15) Bitcoin Core PR Review Club Testing Bitcoin Core 28.0 Release Candidates (21:08) Releases and release candidates LND v0.18.3-beta (51:33) BDK 1.0.0-beta.2 (53:05) Bitcoin Core 28.0rc1 (53:14) Notable code and documentation changes Bitcoin Core #30509 (53:38) Bitcoin Core #29605 (1:00:52)

Mark “Murch” Erhardt and Mike Schmidt are joined by Filippo Merli, Lorenzo Bonazzi, Matt Corallo, Eric Voskuil, and rkrux to discuss ⁠Newsletter #319⁠. News Stratum v2 extension for fee revenue sharing (1:49) OP_CAT research fund (17:53) Mitigating merkle tree vulnerabilities (22:43) Releases and release candidates Core Lightning 24.08 (55:21) LDK 0.0.124 (57:59) LND v0.18.3-beta.rc2 (1:06:19) BDK 1.0.0-beta.2 (1:06:43) Bitcoin Core 28.0rc1 (1:07:27) Notable code and documentation changes Bitcoin Core #30454 (1:15:05) Bitcoin Core #22838 (1:17:41) Eclair #2865 (1:19:56) LND #9009 (1:21:49) LDK #3268 (1:23:33) BIPs #1657 (1:26:55)

Mark “Murch” Erhardt and Mike Schmidt are joined by Jay Beddict to discuss ⁠Newsletter #318⁠. News New Bitcoin Mining Development mailing list (0:48) Selected Q&A from Bitcoin Stack Exchange Can a BIP152 compact block be sent before validation by a node that doesn't know all transactions? (15:03) Did Segwit (BIP141) eliminate all txid malleability issues listed in BIP62? (18:13) Why are the checkpoints still in the codebase in 2024? (22:35) Bulletproof++ as generic ZKP ala SNARKs? (26:28) How can OP_CAT be used to implement additional covenants? (28:13) Why do some bech32 bitcoin addresses contain a large number of 'q's? (32:25) How does a 0-conf signature bond work? (37:29) Releases and release candidates Core Lightning 24.08rc2 (42:45) LND v0.18.3-beta.rc1 (43:13) BDK 1.0.0-beta.2 (43:43) Bitcoin Core 28.0rc1 (45:10) Notable code and documentation changes LDK #3263 (48:15) LDK #3247 (49:10) BDK #1569 (50:13)

Mark “Murch” Erhardt and Mike Schmidt are joined by Bob McElrath and moonsettler to discuss ⁠Newsletter #317⁠. News Simple (but imperfect) anti-exfiltration protocol (0:53) Changes to services and client software Proton Wallet announced (23:33) CPUNet testnet announced (25:38) Lightning.Pub launches (38:52) Taproot Assets v0.4.0-alpha released (39:45) Stratum v2 benchmarking tool released (41:31) STARK verification PoC on signet (42:52) SeedSigner 0.8.0 released (48:48) Floresta 0.6.0 released (50:25) Releases and release candidates Core Lightning 24.08rc2 (51:52) LND v0.18.3-beta.rc1 (52:33) Notable code and documentation changes Bitcoin Core #28553 (53:18) Bitcoin Core #30246 (56:39) Bitcoin Core GUI #824 (1:02:10) Core Lightning #7540 (1:04:20) Core Lightning #7403 (1:05:20) LND #8943 (1:06:13) BDK #1478 (1:07:26) BDK #1533 (1:08:12) BOLTs #1182 (1:11:49) BLIPs #39 (1:12:55)

Mark “Murch” Erhardt and Mike Schmidt are joined by Bastien Teinturier and Hennadii Stepanov to discuss Newsletter #316. News New time warp vulnerability in testnet4 (1:05) Onion message DoS risk discussion (14:20) Optional identification and authentication of LN payers (28:04) Bitcoin Core switch to CMake build system (36:15) Releases and release candidates BDK 1.0.0-beta.1 (53:55) Core Lightning 24.08rc2 (54:10) LND v0.18.3-beta.rc1 (54:29) Notable code and documentation changes Bitcoin Core #29519 (55:01) Bitcoin Core #30598 (59:29) Bitcoin Core #28280 (1:02:18) Bitcoin Core #28052 (1:04:47) Core Lightning #7528 (1:08:01) Core Lightning #7533 (1:10:11) Core Lightning #7517 (1:11:19) LND #8955 (1:13:08) LND #8886 (1:14:39) LND #8967 (1:19:45) LDK #3215 (1:22:13) BLIPs #27 (1:26:27)

Mark “Murch” Erhardt and Mike Schmidt are joined by Matt Corallo, Greg Sanders, Sivaram Dhakshinamoorthy to discuss ⁠Newsletter #315⁠. News Faster seed exfiltration attack (1:24) Block withholding attacks and potential solutions (17:21) Statistics on compact block reconstruction (21:47) Replacement cycle attack against pay-to-anchor (36:23) Proposed BIP for scriptless threshold signatures (42:24) Optimistic verification of zero-knowledge proofs using CAT, MATT, and Elftrace (50:40) Bitcoin Core PR Review Club (33:15) Releases and release candidates Libsecp256k1 0.5.1 (53:11) BDK 1.0.0-beta.1 (53:43) Notable code and documentation changes Bitcoin Core #30493 (54:38) Bitcoin Core #30285 (57:33) Bitcoin Core #30352 (1:02:26) Bitcoin Core #29775 (1:02:39) Core Lightning #7476 (1:08:21) Eclair #2884 (1:08:55) LND #8952 (1:12:10) LND #8735 (1:13:40) BIPs #1601 (1:14:44)

Mark “Murch” Erhardt and Mike Schmidt are joined by Sergi Delgado to discuss ⁠Newsletter #314⁠. News Disclosure of vulnerabilities affecting Bitcoin Core versions before 22.0 (0:56) Optimizing block building with cluster mempool (11:23) Hyperion network event simulator for the Bitcoin P2P network (14:30) Releases and release candidates BDK 1.0.0-beta.1 (41:01) Notable code and documentation changes Bitcoin Core #30515 (41:36) Bitcoin Core #30126 (43:00) Bitcoin Core #30482 (44:18) Bitcoin Core #30275 (45:18) Bitcoin Core #30408 (47:29) Core Lightning #7474 (49:27) LND #8891 (51:21) LDK #3139 (51:57) Rust Bitcoin #3010 (52:48)

Mark “Murch” Erhardt and Mike Schmidt discuss ⁠Newsletter #313⁠. News Varied discussion of free relay and fee bumping upgrades (0:31) Selected Q&A from Bitcoin Stack Exchange Why is restructure of mempool required with cluster mempool? (29:54) DEFAULT_MAX_PEER_CONNECTIONS for Bitcoin Core is 125 or 130? (36:32) Why do protocol developers work on maximizing miner revenue? (38:34) Is there an economic incentive to use P2WSH over P2TR? (42:26) How many blocks per second can sustainably be created using a time warp attack? (45:30) pkh() nested in tr() is allowed? (49:01) Can a block more than a week old be considered a valid chain tip? (51:25) SIGHASH_ANYONECANPAY mediated tx modification (57:35) Why does RBF rule #3 exist? (1:00:35) Releases and release candidates BDK 1.0.0-beta.1 (1:02:05) Notable code and documentation changes Bitcoin Core #30320 (1:02:58) Bitcoin Core #29523 (1:07:42) Core Lightning #7461 (1:10:03) Eclair #2881 (1:11:06)

Mark “Murch” Erhardt and Mike Schmidt are joined by Jonas Nick and Pieter Wuille to discuss ⁠Newsletter #312⁠. News Distributed key generation protocol for FROST (1:37) Introduction to cluster linearization (28:45) Changes to services and client software ZEUS adds BOLT12 offers and BIP353 support (56:15) Phoenix adds BOLT12 offers and BIP353 support (57:02) Stack Wallet adds RBF and CPFP support (57:42) BlueWallet adds silent payment send support (57:59) BOLT12 Playground announced (59:10) Moosig testing repository announced (59:56) Real-time Stratum visualization tool released (1:01:01) BMM 100 Mini Miner announced (1:01:57) Coldcard publishes URL-based transaction broadcast specification (1:02:32) Notable code and documentation changes Bitcoin Core #26596 (1:09:38) Core Lightning #7455 (1:11:27) Eclair #2878 (1:11:58) Rust Bitcoin #2646 (1:13:03) BDK #1489 (1:13:55) BIPs #1599 (1:15:22) BOLTs #1173 (1:17:50) BLIPs #25 (1:18:50)

Mark “Murch” Erhardt and Mike Schmidt are joined by Vojtěch Strnad and Fabian Jahr to discuss Newsletter #311. News (1:00) Bitcoin Core PR Review Club Testnet4 including PoW difficulty adjustment fix (15:14) Releases and release candidates Bitcoin Core 26.2 (37:23) LND v0.18.2-beta (37:42) Notable code and documentation changes Rust Bitcoin #2949 (40:04) BDK #1487 (41:20)

Mark “Murch” Erhardt and Mike Schmidt are joined by Antoine Poinsot and Elle Mouton to discuss ⁠Newsletter #310⁠. News Disclosure of vulnerabilities affecting Bitcoin Core versions before 0.21.0 (0:59) Adding a BOLT11 invoice field for blinded paths (22:17) Releases and release candidates Bitcoin Core 26.2rc1 (36:43) Notable code and documentation changes Bitcoin Core #28167 (37:48) Bitcoin Core #30007 (39:07) Bitcoin Core #30200 (40:37) Core Lightning #7342 (41:33) LND #8796 (42:55) LDK #3125 (45:26) BIPs #1610 (46:21) BIPs #1540 (49:07)