Bitcoin Optech Podcast

Mark “Murch” Erhardt and Mike Schmidt discuss ⁠Newsletter #298⁠. News What would have happened if cluster mempool had been deployed a year ago? (0:42) Changes to services and client software Phoenix for server announced (19:26) Mercury Layer adds Lightning swaps (21:32) Stratum V2 Reference Implementation v1.0.0 released (22:46) Teleport Transactions update (25:09) Bitcoin Keeper v1.2.1 released (28:10) BIP-329 label management software (29:02) Key agent Sigbash launches (31:37) Releases and release candidates Bitcoin Core 27.0 (35:19) BTCPay Server 1.13.1 (41:50) LDK 0.0.122 (42:55) Notable code and documentation changes LDK #2704 (44:40)

Dave Harding and Mike Schmidt are joined by Kulpreet Singh, Chris Stewart, Jameson Lopp, and Joost Jager to discuss ⁠Newsletter #297⁠. News DSL for experimenting with contracts (1:24) Updating BIP2 (15:50) Discussion about resetting and modifying testnet (21:00) Bitcoin Core PR Review Club Implement 64 bit arithmetic op codes in the Script interpreter (37:19) Releases and release candidates HWI 3.0.0 (46:17) Core Lightning 24.02.2 (48:06) Bitcoin Core 27.0rc1 (49:41) Notable code and documentation changes Bitcoin Core #29648 (50:25) Bitcoin Core #29130 (21:00)

Mark “Murch” Erhardt and Mike Schmidt are joined by Antoine Poinsot to discuss ⁠Newsletter #296⁠. News Revisiting consensus cleanup (0:46) Choosing new BIP editors (27:21) Releases and release candidates Bitcoin Core 26.1 (37:22) Bitcoin Core 27.0rc1 (39:09) HWI 3.0.0-rc1 (39:40) Notable code and documentation changes Bitcoin Core #27307 (40:59) Bitcoin Core #29242 (43:50) Core Lightning #7094 (52:59) BDK #1351 (54:41)

Mark “Murch” Erhardt and Mike Schmidt are joined by Dave Harding, Peter Todd, Abubakar Sadiq Ismail, David Gumberg, and Jeffrey Czyz to discuss Newsletter #295. News Disclosure of free relay attack (1:22) Transaction fee sponsorship improvements (9:55) Mempool-based feerate estimation (34:49) Selected Q&A from Bitcoin Stack Exchange What are the risks of running a pre-SegWit node (0.12.1)? (50:30) When is OP_RETURN cheaper than OP_FALSE OP_IF? (55:51) Why does BIP-340 use secp256k1? (56:33) What criteria does Bitcoin Core use to create block templates? (58:08) How does the initialblockdownload field in the getblockchaininfo RPC work? (1:04:45) Releases and release candidates Bitcoin Core 26.1rc2 (1:07:34) Bitcoin Core 27.0rc1 (1:07:55) Notable code and documentation changes Bitcoin Core #28950 (1:17:13) LND #8418 (1:19:07) LDK #2756 (1:23:44) LDK #2935 (1:25:55) LDK #2419 (1:27:39) Rust Bitcoin #2549 (1:32:54) BTCPay Server #5852 (1:33:36)

Mark “Murch” Erhardt and Mike Schmidt are joined by Sebastian Falbesoner, Anthony Towns, and Russell O’Connor to discuss ⁠Newsletter #294⁠. News BIP324 proxy for light clients (1:20) Overview of BTC Lisp (10:44) Changes to services and client software BitGo adds RBF support (38:59) Phoenix Wallet v2.2.0 released (40:11) Bitkey hardware signing device released (44:19) Envoy v1.6.0 released (47:49) VLS v0.11.0 released (49:22) Portal hardware signing device announced (50:54) Braiins mining pool adds Lightning support (51:44) Ledger Bitcoin App 2.2.0 released (54:14) Releases and release candidates Bitcoin Core 26.1rc2 (55:51) Bitcoin Core 27.0rc1 (56:48) Notable code and documentation changes Bitcoin Core #27375 (57:43) Bitcoin Core #27114 (58:59) Bitcoin Core #29306 (1:02:19) LND #8310 (1:09:04) Rust Bitcoin #2458 (1:10:12)

Mark “Murch” Erhardt and Mike Schmidt are joined by ZmnSCPxj, Anthony Towns, and Armin Sabouri to discuss Newsletter #293. News Trustless onchain betting on potential soft forks (1:11) Overview of Chia Lisp for Bitcoiners (14:06) Bitcoin Core PR Review Club Re enable `OP_CAT` (35:48) Releases and release candidates Core Lightning v24.02.1 (50:33) Bitcoin Core 26.1rc1 (51:03) Bitcoin Core 27.0rc1 (52:11) Notable code and documentation changes LND #8136 (54:58) LND #8499 (57:26) LDK #2916 (58:31)

Mark “Murch” Erhardt and Dave Harding are joined by Josie Baker, Salvatore Ingala, and Fabian Jahr to discuss ⁠Newsletter #292⁠. News Updating BIP21 `bitcoin:` URIs (18:07) PSBTs for multiple concurrent MuSig2 signing sessions (46:30) Discussion about adding more BIP editors (58:33) GitLab backup for Bitcoin Core GitHub project (1:11) Releases and release candidates Eclair v0.10.0 (1:03:24) Bitcoin Core 26.1rc1 (1:05:18) Notable code and documentation changes Bitcoin Core #29412 (1:06:53) Eclair #2829 (1:17:29) LND #8378 (1:19:06) BIPs #1421 (1:20:28)

Mark “Murch” Erhardt and Mike Schmidt are joined by Richard Myers, Rijndael, Luke Dashjr, and Jason Hughes to discuss Newsletter #291. News Trustless contract for miner feerate futures (1:31) Coin selection for liquidity providers (7:18) Simple vault prototype using `OP_CAT` (21:15) Sending and receiving ecash using LN and ZKCPs (44:44) Selected Q&A from Bitcoin Stack Exchange Why can't nodes have the relay option to disallow certain transaction types? (49:41) What is the circular dependency in signing a chain of unconfirmed transactions? (53:28) How does Ocean’s TIDES payout scheme work? (34:02) What data does the Bitcoin Core wallet search for during a blockchain rescan? (57:57) How does transaction rebroadcasting for watch-only wallets work? (59:37) Releases and release candidates Core Lightning 24.02 (1:02:20) Notable code and documentation changes LDK #2770 (1:04:20)

Mark “Murch” Erhardt and Mike Schmidt are joined by Gloria Zhao, callebtc, Chris Stewart, Fabian Jahr, and Pierre Corbin to discuss ⁠Newsletter #290⁠. News DNS-based human-readable Bitcoin payment instructions (1:41) Thinking about mempool incentive compatibility (9:50) Cashu and other ecash system design discussion (29:15) Continued discussion about 64-bit arithmetic and `OP_INOUT_AMOUNT` opcode (39:52) Improved reproducible ASMap creation process (49:17) Changes to services and client software Multiparty coordination protocol NWC announced (1:11:00) Mutiny Wallet v0.5.7 released (1:19:07) GroupHug transaction batching service (1:19:48) Boltz announces taproot swaps (1:22:43) Releases and release candidates Core Lightning 24.02rc1 (1:24:07) Notable code and documentation changes Bitcoin Core #27877 (1:24:58) BOLTs #851 (1:29:00)

Dave Harding and Mike Schmidt are joined by Gregory Sanders and Gloria Zhao to discuss Newsletter #289. News Ideas for relay enhancements after cluster mempool is deployed (1:11) What would have happened if v3 semantics had been applied to anchor outputs a year ago? (25:55) Bitcoin-Dev mailing list move (35:47) I Love Free Software Day (37:56) Bitcoin Core PR Review Club Add `maxfeerate` and `maxburnamount` args to `submitpackage` (39:57) Notable code and documentation changes Bitcoin Core #28948 (46:24) Core Lightning #6785 (49:39) Eclair #2818 (50:18) Eclair #2816 (52:29) LND #8338 (56:20) LDK #2856 (56:56) LDK #2442 (59:09) Rust Bitcoin #2451 (59:39)

Dave Harding and Mike Schmidt are joined by Bastien Teinturier and Eugene Siegel to discuss Newsletter #288. News Public disclosure of a block stalling bug in Bitcoin Core affecting LN (1:26) Securely opening zero-conf channels with v3 transactions (17:08) Requirement to verify inputs use segwit in protocols vulnerable to txid malleability (27:00) Proposal for replace by feerate to escape pinning (35:21) Bitcoin-Dev mailing list migration update (51:15) Releases and release candidates LND v0.17.4-beta (1:00:02) Notable code and documentation changes Bitcoin Core #29189 (1:01:13) Bitcoin Core #28956 (1:07:23) Bitcoin Core #29347 (1:10:03) Core Lightning #6985 (1:10:45) Core Lightning #6904 (1:12:54) Core Lightning #7022 (1:14:53) Core Lightning #6936 (1:16:16) LND #8345 (1:18:02)

Mark “Murch” Erhardt and Mike Schmidt are joined by Gloria Zhao and Brandon Black to discuss ⁠Newsletter #287⁠. News Kindred replace by fee (1:10) Opposition to CTV based on commonly requiring exogenous fees (19:11) Selected Q&A from Bitcoin Stack Exchange How does block synchronization work in Bitcoin Core today? (28:14) How does headers-first prevent disk-fill attack? (30:31) Is BIP324 v2transport redundant on Tor and I2P connections? (33:57) What's a rule of thumb for setting the maximum number of connections? (34:57) Why isn't the upper bound (+2h) on the block timestamp set as a consensus rule? (37:01) Sigop count and its influence on transaction selection? (43:22) Releases and release candidates HWI 2.4.0 (48:03) Notable code and documentation changes Bitcoin Core #29291 (48:41) Eclair #2811 (49:23) LND #8167 (52:10) LND #7733 (53:01) LND #8275 (54:01) Rust Bitcoin #2366 (56:34) HWI #716 (58:35) BDK #1172 (58:49) BINANAs #3 (59:29)

Mark “Murch” Erhardt and Mike Schmidt are joined by Niklas Gögge, Bastien Teinturier, Anthony Towns, Gloria Zhao, Nicholas Gregory, and Tom Trevethan to discuss ⁠Newsletter #286⁠. News Disclosure of fixed consensus failure in btcd (1:33) Proposed changes to LN for v3 relay and ephemeral anchors (13:40) New documentation repository (29:56) Changes to services and client software Envoy 1.5 released (45:41) Liana v4.0 released (46:39) Mercury Layer announced (47:46) AQUA wallet announced (57:18) Samourai Wallet announces atomic swap feature (57:49) Releases and release candidates LDK 0.0.120 (58:37) HWI 2.4.0-rc1 (59:11) Notable code and documentation changes Bitcoin Core #29239 (59:37) Eclair #2810 (1:02:16) LDK #2791 (1:05:32) Rust Bitcoin #2230 (1:07:43)

Mark “Murch” Erhardt and Mike Schmidt are joined by Brandon Black, Chris Stewart, Gregory Sanders, and Oliver Gugger to discuss ⁠Newsletter #285⁠. News Disclosure of past vulnerability in Core Lightning (2:15) New LNHANCE combination soft fork proposed (4:59) Proposal for 64-bit arithmetic soft fork (21:08) Overview of cluster mempool proposal (38:25) Updated specification and implementation of Bitcoin transaction compression (45:22) Discussion of Miner Extractable Value (MEV) in non-zero ephemeral anchors (46:51) Releases and release candidates LDK 0.0.119 (56:24) Notable code and documentation changes Bitcoin Core #29058 (57:17) Bitcoin Core #29200 (58:59) Bitcoin Core #28890 (1:00:08) Eclair #2808 (1:01:25) LND #8188 (1:02:09) LND #8096 (1:07:44) LND #8095 (1:09:08)

Mark “Murch” Erhardt and Mike Schmidt are joined by Gloria Zhao, Gregory Sanders, Dave Harding, and Stéphan Vuylsteke to discuss Newsletter #284. News Discussion about LN anchors and v3 transaction relay proposal (1:03) LN-Symmetry research implementation (35:03) Bitcoin Core PR Review Club Nuke adjusted time (attempt 2) (50:01) Notable code and documentation changes LND #8308 (1:05:06)

Mark “Murch” Erhardt and Mike Schmidt are joined by Niklas Gögge, Antoine Riard, Abubakar Sadiq Ismail, Gloria Zhao, Salvatore Ingala, Johan Torås Halseth and SeedHammer Team to discuss Newsletter #283. News Disclosure of past LND vulnerabilities (2:07) Fee-dependent timelocks (25:09) Cluster fee estimation (8:32) How to specify unspendable keys in descriptors (17:48) V3 transaction pinning costs (34:14) Descriptors in PSBT draft BIP (48:19) Verification of arbitrary programs using proposed opcode from MATT (57:52) Pool exit payment batching with delegation using fraud proofs (1:04:59) New coin selection strategies (1:14:36) Releases and release candidates Core Lightning 23.11.2 (1:17:57) Libsecp256k1 0.4.1 (1:18:14) Notable code and documentation changes Bitcoin Core #28349 (1:19:06) Core Lightning #6957 (1:20:21) Core Lightning #6869 (1:21:15) Eclair #2796 (1:21:47) Eclair #2787 (1:22:23) LDK #2781 (1:23:14) LDK #2723 (1:24:16) BIPs #1504 (1:25:00)

Mark “Murch” Erhardt, Dave Harding, and Mike Schmidt discuss ⁠Newsletter #282: 2023 Year-in-Review Special⁠. January Bitcoin Inquisition (10:59) Swap-in-potentiam (14:03) BIP329 wallet label export format (19:32) February Ordinals and inscriptions (20:22) Bitcoin Search, ChatBTC, and TL;DR (41:50) Peer storage backups (43:40) LN quality of service (44:10) HTLC endorsement (47:31) Codex32 (48:33) March Hierarchical channels (50:57) Summary 2023: Soft fork proposals (54:22) April Watchtower accountability proofs (1:04:24) Route blinding (1:05:58) MuSig2 (1:08:36) RGB and Taproot Assets (1:12:47) Channel splicing (1:16:06) May LSP specifications (1:21:10) Payjoin (1:23:07) Ark (1:27:40) June Silent payments (1:30:33) Summary 2023: Security disclosures (1:32:34) July Validating Lightning Signer (1:36:10) LN developer meeting (1:38:00) August Onion messages (1:38:28) Outdated backup proofs (1:41:52) Simple taproot channels (1:44:39) September Compressed Bitcoin transactions (1:46:40) Summary 2023: Major releases of popular infrastructure projects (1:48:19) October Payment switching and splitting (1:49:46) Sidepools (1:51:30) AssumeUTXO (1:55:28) Version 2 P2P transport (1:55:51) Miniscript (1:57:18) State compression and BitVM (2:00:07) November Offers (2:05:53) Liquidity advertisements (2:08:26) Summary 2023: Bitcoin Optech (1:11) December Cluster mempool (2:11:10) Warnet (2:13:12)

Mark “Murch” Erhardt and Dave Harding are joined by Bastien Teinturier and Rodolfo Novak to discuss Newsletter #281. News Discussion about griefing liquidity ads (0:46) Changes to services and client software Stratum v2 mining pool launches (15:43) Bitcoin network simulation tool warnet announced (16:31) Payjoin client for Bitcoin Core released (17:30) Call for community block arrival timestamps (18:44) Envoy 1.4 released (21:41) BBQr encoding scheme announced (22:09) Zeus v0.8.0 released (22:45) Selected Q&A from Bitcoin Stack Exchange What are all the rules related to CPFP fee bumping? (25:16) How is the total number of RBF replaced transactions calculated? (29:41) What types of RBF exist and which one does Bitcoin Core support and use by default? (31:37) What is the Block 1,983,702 Problem? (34:48) What are hash functions used for in bitcoin? (45:12) Releases and release candidates LND 0.17.3-beta (51:59) Notable code and documentation changes LDK #2685 (52:22) Libsecp256k1 #1446 (53:04) BTCPay Server #5389 (53:36) BTCPay Server #5490 (59:54)

Mark “Murch” Erhardt and Mike Schmidt are joined by Pieter Wuille and Matthew Zipkin to discuss Newsletter #280. News Cluster mempool discussion (0:57) Testing with warnet (32:42) Bitcoin Core PR Review Club Testing Bitcoin Core 26.0 Release Candidates (43:18) Releases and release candidates Bitcoin Core 26.0 (45:30) LND 0.17.3-beta.rc1 (57:41) Notable code and documentation changes Bitcoin Core #28848 (58:49) LDK #2540 (59:49)

Mark “Murch” Erhardt and Mike Schmidt are joined by Lisa Neigut and Bastien Teinturier to discuss Newsletter #279. News Update to the liquidity ads specification (1:00) Selected Q&A from Bitcoin Stack Exchange Is the Schnorr digital signature scheme a multisignature interactive scheme, and also not an aggregated non-interactive scheme? (38:49) Is it advisable to operate a release candidate full node on mainnet? (41:40) What is the relation between nLockTime and nSequence? (44:40) What would happen if we provide to OP_CHECKMULTISIG more than threshold number (m) of signatures? (52:18) What is (mempool) policy? (54:30) What does Pay to Contract (P2C) mean? (57:31) Can a non-segwit transaction be serialized in the segwit format? (58:18) Releases and release candidates Core Lightning 23.11 (1:00:05) Bitcoin Core 26.0rc3 (1:03:31) Notable code and documentation changes Rust Bitcoin #2213 (1:04:55) BDK #1190 (1:09:04)