Bitcoin Optech Podcast

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)

Mark “Murch” Erhardt and Mike Schmidt are joined by René Pickhardt to discuss ⁠Newsletter #309⁠. News Estimating the likelihood that an LN payment is feasible (1:04) Selected Q&A from Bitcoin Stack Exchange How is the progress of Initial Block Download (IBD) calculated? (31:25) What is `progress increase per hour` during synchronization? (33:50) Should an even Y coordinate be enforced after every key-tweak operation, or only at the end? (34:45) Signet mobile phone wallets? (37:28) What block had the most transaction fees? Why? (39:01) bitcoin-cli listtransactions fee amount is way off, why? (41:48) Did uncompressed public keys use the `04` prefix before compressed public keys were used? (44:57) What happens if an HTLC's value is below the dust limit? (46:34) How does subtractfeefrom work? (47:11) What's the difference between the 3 index directories blocks/index/, bitcoin/indexes and chainstate? (51:19) Releases and release candidates LND v0.18.1-beta (52:18) Bitcoin Core 26.2rc1 (53:02) Notable code and documentation changes Bitcoin Core #29575 (53:29) Bitcoin Core #28984 (56:38) Core Lightning #7388 (1:00:28) LND #8734 (1:03:24) LDK #3127 (1:03:59) Rust Bitcoin #2794 (1:05:39) BDK #1395 (1:07:05) BIPs #1620 (1:08:55) BOLTs #869 (1:11:57)

Mark “Murch” Erhardt and Mike Schmidt are joined by Jameson Lopp and Valentine Wallace to discuss ⁠Newsletter #308⁠. News Disclosure of vulnerability affecting old versions of LND (0:54) Continued discussion of PSBTs for silent payments (7:32) Changes to services and client software Casa adds descriptor support (10:55) Specter-DIY v1.9.0 released (40:52) Constant-time analysis tool cargo-checkct announced (41:26) Jade adds miniscript support (43:15) Ark implementation announced (45:32) Volt Wallet beta announced (46:42) Joinstr adds electrum support (47:20) Bitkit v1.0.1 released (47:50) Civkit alpha announced (48:20) Releases and release candidates Bitcoin Core 26.2rc1 (49:01) Notable code and documentation changes Bitcoin Core #29325 (50:11) Eclair #2867 (52:04) LND #8730 (52:33) LDK #3098 (28:14) LDK #3078 (32:35) LDK #3082 (33:53) LDK #3103 (35:18) LDK #3037 (38:07)