Mike Schmidt

Inside the "Kernel Project" & the Bitcoin Core Development Process w/ Core Dev Stéphan Core developer Stéphan sits down with Bitcoin Magazine's @brian_trollz to explain how the Kernal and multiprocess projects are reshaping Bitcoin Core for long-term reliability.

A new release candidate of Bitcoin Core, v31.0rc1, is available for testing. This is a new major release, and follows v30.2. Work-in-progress release notes are here: github.com/bitcoin-core/b… Binaries are available here: bitcoincore.org/bin/bitcoin-co…

Attack Blocks We examine “attack blocks”, Bitcoin blocks constructed such that they are difficult to validate This attack was first proposed Jan 2013: A 1MB transaction could take over 3 minutes to verify (BIP-54 fixes this) bitmex.com/blog/attack-bl…

Jonathan Harvey-Buschel (@jonhbit) joined Optech to discuss Newsletter #396: News ● Collision-resistant hash function for Bitcoin Script (0:30) ● Continued discussion of Gossip Observer traffic analysis tool (8:58) Releases and release candidates ● BDK wallet 3.0.0-rc.1 (28:04) Notable code and documentation changes ● Bitcoin Core #26988 (30:39) ● Bitcoin Core #34692 (32:22) ● LDK #4304 (33:21) ● LDK #4416 (35:41) ● LND #10089 (38:01) ● Libsecp256k1 #1777 (39:46) ● BIPs #2047 (42:39) ● BOLTs #1316 (46:42) ● BOLTs #1312 (47:26)

Bitcoin Optech newsletter #396 is here: - describes a collision-resistant hash function using Bitcoin Script - summarizes continued discussion of Lightning Network traffic analysis - Optech Newsletter #396 Podcast bitcoinops.org/en/newsletters…

Jon McAlpine, Antoine Poinsot (@darosior), Mike Casey (@theblackmarble), and Ethan Heilman (@Ethan_Heilman) joined Optech to discuss Newsletter #395: News ● A standard for stateless VTXO verification (1:31) ● Draft BIP for expanded `nVersion` nonce space for miners (1:23:45) Changing consensus ● Extensions to standard tooling for TEMPLATEHASH-CSFS-IK support (13:52) ● Hourglass V2 update (25:40) ● Algorithm agility for Bitcoin (51:15) ● The limitations of cryptographic agility in Bitcoin (1:05:15) Releases and release candidates ● Bitcoin Core 28.4rc1 (1:36:53) Notable code and documentation changes ● Bitcoin Core #33616 (1:38:30) ● Bitcoin Core #34616 (1:42:23) ● Eclair #3256 (1:46:20) ● Eclair #3258 (1:48:34) ● Eclair #3255 (1:50:14) ● LDK #4402 (1:52:27) ● LND #10604 (1:53:56) ● BIPs #1699 (1:55:34) ● BIPs #2106 (1:57:30) ● BIPs #2068 (2:01:28) ● BOLTs #1301 (2:04:54)

@giacomozucco @FractalEncrypt

@FractalEncrypt I should have written "boring" with airquotes. :)

Yes, we need "builders" all right! But not for fancy, novel, shining "use cases": for trivial, boring, basic-bitch ones, which are still shitty! We don't have decent and simple tooling yet for acquiring sats, hodling sats and spending sats, with some minimum level of privacy and state-resistance (which is the ONLY reason for Bitcoin to even exist in the first place). And you dream of subsidizing a new wave of bored Silicon-Valley kids with anxiety issues and pronouns in bio, to further waste our time hyping "smart contracts", "NFT" scams, "agentic" bots and "Quantum" nonsense? Fuck them. They can stay in the current-thing fiat bubble. We need cypherpunk engineers with long-enough attention spam to focus on real, boring things. It's 2026, and when a normie asks me a tool to use Bitcoin properly, I *don't* have a clean, simple answer. I teach them to stack sats avoiding KYC, but bisq and robosats and vexl are far from perfect and standard. People use shit like binance. I teach them to hodl keys properly, but airgapping and multisig with coldcard, seedsigner, liana, sparrow, nunchuck are far from perfect and standard (let alone if they want to manage inheritance). I teach them to use the Lightning Network to pay small amounts, but really usable LN last-mile security models, like arks and mints, are still early and don't have good tooling yet, and wallets with decent, contact-based UX, like Blitz, are still niche and experimental. I teach them to run nodes instead of blindly trusting third parties and leaking sensitive information, and to conjoin from and to cold-storage, but even with node-in-a-box tools like Start9+JAM, syncing a full node is still terrible UX, and running joinmarket effectively far from trivial. And what about having all those things in a single consistent app or framework? Still a wet dream! Fuck your imaginary, scammy "new use cases". Shitcoins already exist for those. Let's fix the real ones.

Niklas finds bugs across Bitcoin and Lightning implementations. He added a bunch of testing in Bitcoin Core to find bugs. He created and open sourced his own fuzz testing framework so he could find even more bugs, faster. He found and fixed CVE-2024-35202 a high severity bug that allowed arbitrary crashing of Bitcoin Core nodes. And much more. Thank you, @dergoegge, and heres to four years 🍻

Correction, the Optech Recap X/Twitter live stream will be at 16:30 UTC today. We will be joined by Jgmcalpine, Antoine Poinsot (@darosior), Mike Casey (@theblackmarble), and Ethan Heilman (@Ethan_Heilman)

@boomer_btc @Crypto_Mags bitcoin.stackexchange.com/a/38998

Certainly this is true in spirit but the total should not add up to 21M. There are several instances where the block reward was not fully claimed in the coinbase transaction. The most famous being a block in which the miner shorted themselves by 12.5 Bitcoin. As a result the amount left to be mined is less than expressed here.

While we were all monitoring the Iran situation, Bitcoin quietly hit a major milestone: the 20 millionth Bitcoin was mined

@Cipherhoodlum @hodlonaut Nah, Antoine ran into them in the hallway at the MIT Bitcoin Expo IIRC.

@hodlonaut I recall that @bitschmidty introduced them to Citrea!

1/ There's a narrative circulating that Citrea had nothing to do with the OP_RETURN uncap. That Citrea didn't need it. Didn't ask for it. Was just caught in some drama it didn't start. This thread explores what the people who pushed the change actually said. 🧵

@brian_trollz @mattkratter @jonatack @dergoegge x.com/bitschmidty/st…

This is just amazing. @mattkratter 1) calls @jonatack "One of the most prolific Core devs". No. I love you Jon, and you have done a lot, but you are a FAR cry from that. 2) Then he frames an article written by the Core developer (@dergoegge) working on security testing and disclosures himself as "a superficial thing written by Bitcoin Magazine." Matt Kratter is just a conman, plain and simple.

Cluster Mempool is foremost a local node improvement. It optimally sorts unconfirmed transactions, which makes it faster for your node to process transactions and build blocks, and it optimizes fees from block templates—regardless of what transactions you admit to your mempool.

@giacomozucco @zndtoshi Hmm I didn’t login to this so this is AI designated

@zndtoshi @bitschmidty always in the middle, so diplomatic :D

Launching Consensus.health website! It's an aggregator of Twitter(X) sentiment in regards to the debates of the day. For now the big debate is bip110. I had created a crawler that scanned 20k bitcoiners and tried to see who had an opinion about this topic and categorize them between Approval, Neutral and Against. Also anyone can log in with his twitter account and choose a position. Of course the sentiment expressed here is only from the people that chose to participate and is not indicative of complete community consensus. The size of the avatars is proportional to the number of followers of the said account. Hope you enjoy it.

@GhostofMapl See also: github.com/janb84/bitcoin…

"bitcoin-tui", made for fun.... a TUI style dash that connects to bitcoind. Panels and panes resizable, and each pane is drag and droppable.

"A look at BIP 54, a softfork proposal to fix four outstanding bugs in Bitcoin's core consensus protocol."

Bitcoin Optech newsletter #395 is here: - describes a standard for verifying VTXOs across different Ark implementations - links to a draft BIP for expanding the miner-usable nonce space in the block header’s nVersion field - points to extensions to standard tooling for TEMPLATEHASH-CSFS-IK support - summarizes updates to the Hourglass V2 proposal - examines perspectives on cryptographic algorithm agility for Bitcoin - Optech Newsletter #395 Podcast

@frigorifer1 @hodlonaut To be clear, without this PR they would be marked deprecated, but they could still be used.

@hodlonaut Thanks to @bitschmidty who wrote PR #33453 we can still use -datacarrier and -datacarriersize now, because in original v30 they were supposed to be ignored. github.com/bitcoin/bitcoi…

1/ In 2025 Bitcoin Core removed a decade-old mempool policy default — a configurable limit on how much non-financial data nodes would relay. OP_RETURN was effectively uncapped. Not a consensus rule. A default setting. But defaults govern what most of the network does. Which governs what miners see. Which governs what gets mined. The justification: it wasn’t working anyway, data was getting in through a loophole. What wasn’t disclosed: that loophole had been deliberately kept open. Here’s the documented sequence. 🧵

@BitMEXResearch @SomsenRuben Make it a BIN(ANA) github.com/bitcoin-inquis…

On the issue of whether Ordinals/RDTS should get BIP numbers. While I am in the pretty much "everything should get a number" camp, since there are infinite numbers. It's worth pointing out that RDTS is now known as BIP-110. Had Ordinals been given a number, it would probably still be known as Ordinals

The Ordinals BIP got rejected Short summary: we weighed pros and cons, seemed to fall slightly to the con side, but nobody felt strongly enough about it so it sat in limbo. A decision had to be made, and eventually one of us did. I'll share more of my thoughts in this thread👇

Thank you @hongkim__ @HHorsley and the @Bitwise team for supporting Brink, OpenSats, HRF, and Bitcoin open source 🧡