matt
Matt Corallo

10th known contributor to Bitcoin Core. Now Full-Time Open-Source Bitcoin+Lightning Projects at Spiral (Part of Block).

Public Key

npub185h9z5yxn8uc7retm0n6gkm88358lejzparxms5kmy9epr236k2qcswrdp

NIP-05 Address

matt@bitcoin.ninja

NIP-57 Address

matt@bitcoin.ninja

Profile Code

nprofile1qqsr6tj32zrfn7v0pu4aheaytdnnc6rluepq73ndc2tdjzus34gat9qpzemhxue69uhhyetvv9ujuurjd9kkzmpwdejhgqg3waehxw309ahx7um5wgerztnrdaksfpc2jj

Publishing to

relay.primal.net

nostr21.com

nostr.oxtr.dev

Author Public Key

npub185h9z5yxn8uc7retm0n6gkm88358lejzparxms5kmy9epr236k2qcswrdp

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Last Notes

2025-02-27 13:19:31

Reminder for Bitcoin devs:
When you push code, organized crime is watching.
When you add that dependency, North Korea is trying to comprise its dependencies.
When you leave your laptop unlocked in public, you don’t know who’s gonna hit a few keys.
Stay vigilant. It’s not a lot more work to be careful and avoid dependencies, but it’s a ton of work to clean up after someone loses a billion dollars.

2025-02-24 19:35:08

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Not thinking of one single thing, but there’s plenty of ways fingerprinting different users is likely possible. If you have 10K withdraws per user you can probably cluster the blinded paths many of them are using, add on top features which may identify specific clients and you can probably do pretty well. Obv you can’t tell the difference been any two invoices for different Phoenix (or other wallet with a fixed LSP (set)) wallets, but across wallets I’m skeptical it’s robustly private.

2025-02-21 21:39:32

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Sadly there kinda isn’t one - every other browser is just a Chromium skin with all the Google-pushed crap either neutered or still there. If you’re on a Mac, it’s Firefox or Safari.

2025-02-21 02:41:31

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(For the non-New Yorkers there is no 9 train, yet I just rode it)

2025-02-20 17:17:11

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You can do LN-on-Ark, indeed, which addresses some of the Ark LSP liquidity issues (without the trust model tradeoff), though you still require somewhat more liquidity than lightning natively, which seems pretty expensive.

2025-02-19 18:06:59

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Try being colorblind, then you won’t even notice it!

2025-02-19 16:16:32

Over the past few years Bitcoiners went from dismissing Lightning to cheering on custodial solutions. While many of those solutions have great properties and make sense for low-balance wallets, we shouldn’t lose sight of the goal - great non-custodial UX that Bitcoiners actually *want* to use.
Luckily we have the tech for it (now), we just need the motivation and resources to build great wallets using it!
https://spiralbtc.substack.com/p/custodial-solutions-are-not-solutions

2025-02-18 02:41:40

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I believe DEMAND’s work is related/intends to use the protocol, though.

2025-02-17 18:09:10

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Indeed, OCEAN’s approach leaves a long trail in the DB. I addressed this a bit more in the note below, but I think in practice the (bulk) withdraw you’d do with ecash would end up having similar privacy issues as today’s approach. You obviously can’t withdraw each single sat by itself (the fees would dominate, even on lightning), so you bulk-withdraw in batches. You’d have to have every user have the same bulk-withdraw randomization logic, with fresh BOLT12 (or different ecash mints) to withdraw to each time (otherwise you’d have clear fingerprints in the withdraw batches). And even then I’d bet with enough BOLT 12 blinded paths you’d be able to cluster most withdraws :/.
This just isn’t as simple as you’re thinking. I agree there’s a world where on an extreme margin this could improve privacy, but it’s a really tiny margin and a pool motivated to go look would probably be able to see through almost all of it :/
#nevent1q…slh4

2025-02-17 17:57:50

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They’re really not, though. Also important to point out that you can’t “just” withdraw all your tokens piecemeal as the fee to do that (even over lightning) would dominate, and the intermediate hoops through the lightning network plus withdraw steps would almost certainly be a unique fingerprint. I’m quite confident you’d end up with zero additional privacy against a pool that really dug into it. #nevent1q…f2cn

2025-02-16 22:47:53

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Oh but you *know* there’s a lot of people who are gonna be entirely outraged at this when they find out.

2025-02-11 02:37:45

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#nevent1q…w0dt

2025-02-11 02:36:52

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I don’t think that’s fair. If I follow a lot of people I might want the top posts from those I follow since I last logged in on top. There are tons of options that aren’t terrible and aren’t just tuned scroll-encouragement.

2025-02-10 18:38:53

I think people here underestimate just how many users Twitter/X has lost over the last year (not counting AI bots…). Looking back at people who were a major part of The Conversation a few years ago most of them simply don’t post anywhere anymore (or a few do on Bluesky). Turns out a bad algorithm is worse than none.
Nostr isn’t losing the user race, people just stopped posting.

2025-02-09 12:54:26

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And, yea, Elon personally spends *wayy* too much time on Twitter getting egged on by the right-cult. It’s not healthy for him :/

2025-02-07 22:22:06

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I am without KYC. Geoip US/California.

2025-02-07 18:15:34

It’s a real shame the US outlawed this starting next year.
Bigger shame the Bitcoin community isn’t constantly beating the drum, too….making it illegal to pay with bitcoin (via a payment processor) without KYC is nuts! #note1k87…nxwv

2025-02-07 03:48:08

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No, for air traffic controllers themselves. There’s several lawsuits over it, it was…. Really poorly done.
For NASA I haven’t seen any evidence of any real discrimination and I’d be surprised to learn any different than your claim.

2025-01-30 14:10:06

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How is that sus? He *tweeted his exit tax check and Bitcoin holdings*. This isn’t because someone posted about it on Reddit 🤦‍♂️

2025-01-30 11:59:18

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Only post-subsidy

2025-01-29 17:50:02

Roger Ver: posts publicly about how much bitcoin he has
Also Roger: posts his (obviously underpaid) exit tax payment on Twitter
…
Paul Sztorc: it must be Greg’s fault the IRS found out! #note13jl…25qh

2025-01-27 03:31:16

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Except nothing does or will ever bother to support blinded paths outside of BOLT 12. Luckily BOLT 12 has two other important features that users desperately need so wallets that adopt it get a way better UX.

2025-01-24 14:56:28

Underrated advantage of paying in bitcoin - your orders don’t get randomly cancelled due to overzealous anti fraud systems.
As the internet becomes more and more and more bot-ridden, everything ends up with aggressive bot detection that invariably blocks lots of people. This also applies to online shopping, where suddenly some merchants simply block a lot of their potential customers due to chargeback risk. If I pay in bitcoin, they can process the order and not spend money on broken anti-fraud systems.
I’m literally trying to order a damn pan and can’t 🤦‍♂️

2025-01-22 12:20:09

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The implication of the samurai case (at least the second charge) is that modern self-custody wallets would be illegal. That isn’t just seeking power, that’s seeking to protect Bitcoin.

2025-01-22 01:13:57

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It would be nice, but an executive statement of the charging being an overreach would also be good, and a pardon is implicitly that. I’d rather fight that fight with a more…. Promising defendant tbh.

2025-01-22 01:00:33

The bitcoin community has real political power, it’s time we exercise it.
#FreeSamorai #note1q7d…9v7e

2025-01-19 18:32:12

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Yep

2025-01-08 04:21:16

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Yea, which, how do I decide? Also how do I do so without impacting followers on different relays from seeing my posts?

2025-01-08 04:20:37

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Damus is the only app that’s ever worked well for me. Sadly the spam is basically random words and images from random accounts.

2025-01-08 04:13:00

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I’d take that action.

2025-01-08 04:12:36

Okay, my mentions are now filled with spam. I guess that’s cause I “picked bad relays”? How do I (a normal user who doesn’t have the time to investigate the relay offerings out there) fix this?

2024-12-28 06:47:07

Run a bitcoin payment processor so that normie merchants can accept bitcoin and we can spend bitcoin (which was half the damn point)? Congrats you have to ask for the socials of people paying 🤦‍♂️ #note1vxz…j98n

2024-12-23 09:51:17

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Sadly I don’t recall that being his argument…. I don’t think he’d even considered “sometimes government isn’t just and good” at all until I highlighted the possibility of voters electing someone “bad”.

2024-12-22 23:21:15

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A backdoor is a backdoor whether it’s described in the documentation and public or not.

2024-12-22 22:26:45

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The app description explicitly lists a privacy backdoor for governments? It’s literally the design of the GNU Taler project (to build ecash with a limited backdoor to prevent money laundering/tax evasion).

2024-12-22 16:53:44

I once had a discussion with a GNU Taler dev, who argued with a straight face that the government should have a (limited) backdoor into financial systems despite voters sometimes electing bad people because, and I’m dead serious here, the German voters would never elect someone with as authoritarian tendencies as Trump.
I guess he missed his history lessons…in literally every year of school there lol #note1vhh…jzmn

2024-12-19 05:57:33

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Sure it makes sense, just funny to watch NGU bitcoiners care more about the fed than anything.

2024-12-19 04:18:41

Anyone else find it kinda ironic that the Bitcoin 100k push came after an off-hand comment by the Fed chair, and now Bitcoin is down 5% on Fed chair comments?

2024-12-18 22:27:34

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Tyler from your team made the graphs for me!

2024-12-18 20:42:54

LDK’s new pathfinding tuning is pretty predictive of the real world! https://image.nostr.build/7e94329c4fe010a97736a339b2269b38d6bb55207d394b87e8f68938ff18d525.jpg

2024-12-16 04:19:38

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Yes, I saw your post, I thought it was quite clever! That said, I think the Taproot approach is slightly cleaner - it allows wallets more flexibility (eg they could use a static PQ key for all their addresses, and no one would ever know unless they were used).
In terms of one-time vs larger-signatures, my mental model here is basically this stuff will only be used on the margin. Wallets that upgrade today and that people don’t touch for two decades will be safe, but wallets people sure actively using in five or seven years might use other, newer options for PQC. Thus, a bit worse design is fine, if it makes the solution more bulletproof. Now, that said, maybe that’s indeed an argument for a single-use scheme, just because it’s simpler to implement.

2024-12-15 22:34:27

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I’m told this was in fact a design goal of Taproot, but somehow I wasn’t aware of it. 🤷‍♂️

2024-12-15 22:29:51

Turns out Taproot is great for post-Quantum in Bitcoin. https://groups.google.com/g/bitcoindev/c/8O857bRSVV8

2024-12-15 01:15:50

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Vinny with a bad take? Huh, whod’a thunk it.

2024-12-13 14:48:25

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So disappointing that I’m their rush to scale Bluesky dropped all the decentralized moderation architecture they built. Just embarrassing.

2024-12-11 15:32:19

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Nor that. Taking all the counts and adding up the total maximum sentence for each is not how federal sentencing works (and not just any kind of “in theory the judge could….” kinda way, they can’t do that).

2024-12-11 15:28:49

No, Roger is not facing 109 years in prison. That’s not how federal sentencing works, that’s never how federal sentencing has ever fucking worked. Stop quoting morons who don’t know how things work.

2024-12-11 14:04:53

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Sure, you can just hide the message behind a tap - removes the message from the payments list but users can still see it. Sadly, I think you’re right - and frankly dunno that the messages are worth having 🤷‍♂️

2024-12-11 13:30:51

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Wallets should just not display the message (under a certain threshold?) until the user taps into the transaction. That takes the value away for advertisers but retains the original purpose.

2024-12-11 13:29:12

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The better solution is to just not display the Zap/message under a threshold. That’s what many wallets already do AFAIU. Rejecting money bound for a user sucks, tho, even if it’s tiny, especially since users currently expect that to work.

2024-12-11 13:26:27

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Nah, for travel you need bag structure to put things in their place and have them all stay there. Especially important for clothes to avoid wrinkles.

2024-12-11 13:25:40

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I mean if it has a hard back I’m not sure why collapsible helps? Pushing an empty full suitcase isn’t all that hard if it has four wheels…
But, yea, a proper four wheel suitcase (I’m partial to TravelPro over Away but whatever) is the way to go for actual travel use-cases - sturdy, not annoying cause the sides are always collapsing when you’re trying to put stuff in, hard sides also give structure for where to place items as you add them, etc. But for events…I dunno, if you really want something collapsible, I dunno what’s good, not a lot of competition for such things because they suck for travel.

2024-12-11 05:44:48

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Well see, there’s your problem, you prefer terrible suitcases.

2024-12-11 01:46:45

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Why are you sending automated abuse emails?

2024-12-11 01:43:20

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His book came out *after* this “all started happening to him”. He’s just an asshole who’s sad he lost and can’t accept it.
(Sure prison time of that long for tax evasion is probably not right either, but there are worse miscarriages of justice)

2024-12-11 01:40:54

Snakes who spent years trying to destroy Bitcoin should stay in their holes rather than trying to emerge and claim they were the savior all along.

2024-12-05 02:39:13

And that’s 100k

2024-12-04 07:08:40

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Sure, but once you have given them a bitcoin wallet and they have some bitcoin and are used to bitcoin transactions being instant, suddenly them sending their funds back out being super slow is gonna piss them off :(

2024-12-04 05:48:00

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Right, the lightning -> on-chain direction is instant, but the issue is the other way.

2024-12-04 04:14:55

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I interpreted your design as “hold funds in a custodial lightning wallet until they get big enough, then pull them on chain”. The problem with step two is now to send them back out over lightning you first have to do an on-chain transaction to set up a swap, which will be a terrible UX for paying lightning invoices.
The design makes a hell of a lot of sense otherwise (it’s kinda the old mutiny model), just have to hold the funds in lightning channels.

2024-12-04 01:03:51

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You really want the withdrawn funds to still be able to pay to a lightning invoice for decent UX, though, so you really need to withdraw to a channel.
Users get really sad when they can’t send their full balance in one transaction to any payment method supported.

2024-12-01 03:43:28

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That does not solve the issues, sadly far from it.

2024-12-01 03:18:10

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Congrats!

2024-12-01 03:17:05

Decentralization is hard. Everything sucks. #note17d3…sjjd

2024-12-01 02:08:48

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(The LDK “historical model”, however, seems to do okay, keeping histograms of the liquidity bounds)

2024-12-01 02:04:09

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Err, no, sorry, that’s wrong. Degrading instantly is bad (the learning does help!), but the model itself is worse than the naive “I dunno, 50/50 always” “model”, even when you learn.

2024-12-01 01:31:06

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At least my initial analysis of the data seems to say that degrading instantly is better than any other time constant 😭. (May just be some nasty bug in the way we’re calculating probabilities?)

2024-11-30 04:10:38

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Dunno if you saw https://bluematt.bitcoin.ninja/2024/11/22/ln-routing-replay/ but I recently started being more rigorous about our pathfinding scorer. Might be something to play with, it seems like the simple “just keep upper and lower bound on each channel’s liquidity” approach performs *worse* than always assigning each hop a 50% success probability. Keeping a histogram of those bounds, though, does reasonably good.

2024-11-26 20:10:46

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Sudden distribution of cash to a bunch of people could cause a nontrivial bump in spending, offsetting the crash in spending being predicted due to layoffs and other economic headwinds. It was mostly a joke, though, I don’t think there’s that many people with that much bitcoin trying to sell that much bitcoin with that much demand for bitcoin…

2024-11-26 16:29:20

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Bitcoin preventing the post-high-interest-rates 2025 recession that everyone is predicting would be kinda wild.

2024-11-26 16:26:17

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The term developed, I think, because the rest of non-Bitcoin crypto also goes in cycles. Many of those folks aren’t really all that aware of the Bitcoin halving, even though the usual pattern is a Bitcoin price spike post-halving, then some of that money rotates into ETH/etc as the Bitcoin run-up loses steam, then as the ETH/etc run-up loses steam the shitcoin/memecoin/garbage pump starts.
Lots of the ETH/memcoin bros don’t really think about Bitcoin’s halving so they just see a cycle, even though it’s driven by Bitcoin.

2024-11-25 00:50:36

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The options are that or constantly be annoying other people cause you aren’t doing stuff you promised them to keep focus 😭

2024-11-25 00:42:18

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#nevent1q…eegr

2024-11-24 19:12:07

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Yea, I mean the ETH zkRollups are super centralized but to some extent that’s a consequence of these things being hard to build so they need an “escape valve” in practice. There’s not a lot of motivation to remove that but I assume it’ll get removed eventually…. just may be a while.
I do think it’s somewhat informative that ETH only built *rollups*, which certainly don’t have a huge scalability multiple themselves (doubly so for payments, though it’s important to note ETH is trying to scale computation, not payments).

2024-11-24 19:06:12

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There’s a bunch of research on the limits of things - Shielded CSV/rollups (though want to see the limits of a CSV thing if we build a version you can do lightning on top of), Ark/timeout trees is a cool set of ideas that feels like it could be extended, etc. The results certainly don’t point to us having any silver bullets, but I think some of those things probably with some more tweaks may give us a nice direction. But certainly want more analysis.

2024-11-24 16:00:30

This is much better phrased than I can. I’m really, really happy that lots of people are doing *research* into how and what kind of covenants get us the best outcome, but that doesn’t mean we need to rush into anything, maybe the opposite. #note1yae…4aq6

2024-11-24 12:34:50

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No one will ever use congestion control as defined by CTV.

2024-11-24 12:34:17

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I don’t think LN-symmetry solves real user pain points. It makes software simpler, and maybe is important if we move towards multi-party channels, but that’s a ways off.

2024-11-24 00:43:45

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I think interesting ideas using it were eventually proposed…..after most people had given up on CTV 🤷‍♂️

2024-11-24 00:43:02

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Yea, I think this is basically why most people dismissed congestion trees entirely when CTV came out…

2024-11-24 00:40:37

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Not sure which numbers you’re referring to, but I think I agree with the *need*, just strongly disagree with the idea that we have any great solutions. From where I sit, the ideas for scaling using covenants often don’t provide all that much scale, and almost always make other tradeoffs.
IMHO one of the more compelling ideas is timeout trees (which sadly was proposed after people had kinda given up on CTV). But it makes a huge tradeoff - if you get screwed it costs you 10-20x more to FC than Lightning. Worse, an operator can create a “ghetto” of poor users and screw them all to steal from them. *but* it gets you great optimistic-case scaling!
Most things end up looking like that, and it leaves me pretty unexcited…except that the research is moving at a clip! I’m excited to see what the research comes up with, in the mean time I’m still building lightning.

2024-11-23 21:54:27

I responded on Twitter too, but this is such a strange rant to me.
Bitcoin Core (contributor)’s current push for better mempool policy is *directly* related to multi-party UTXO ownership and scaling. It specifically substantially improves lighting in practice today, and will certainly be required for any future scaling technologies.
In the mean time, lots of folks (like James) continue to do research into how to scale Bitcoin (and cryptocurrencies generally). There’s no reason to care if that happens from Bitcoin Core contributors or others, and we’re still really far from having any particularly good ideas on this front. As that research continues, there’s no reason for concrete software towards short-term soft-forks. #note16h9…tlgm

2024-11-23 17:39:13

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To be fair, we’ve also cut the bandwidth needed to stream live video by many multiples.

2024-11-17 22:31:18

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But, yea, people love filter bubbles (censorship being just one way to get that), that’s why most people are on nostr, too! :p

2024-11-17 22:23:58

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I think having an algorithmic feed resonates with people a hell of a lot more, certainly drove early adopters.

2024-11-17 22:11:21

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IOW there seems to be a string desire on here to dismiss Bluesky for trivial reasons (“not decentralized”/“they got MSM coverage so the user growth doesn’t mean anything”/etc) rather than admit they’ve built a product that resonates with a large number of people and that has cool features we should learn from!

2024-11-17 21:55:38

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I don’t *think* it will necessarily become properly decentralized, but rather that it totally *could* and they are working toward it (whether they run out of resources before they get there I dunno), thus I think dismissing Bluesky as “not decentralized, next” is naive.
But I can tell you for sure there the “custom feeds” feature, at a minimum, led to substantial early adopter/evangelist momentum. To a much lesser extent the decentralized labeling/moderation/censorship feature as well.
Even if they didn’t drive material user adoption, they’re cool features we should be learning from, not dismissing the whole thing “because it’s not decentralized”.

2024-11-17 21:08:07

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Not sure there’s much else in that post? Only other point you made is that the only other relays are mostly for hobbyists stuff, which I think is mostly true. Don’t disagree so why respond to it :).

2024-11-17 21:05:57

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Yea but in practice (a) clients mostly don’t, and for very good reason - probably you don’t want to leak your IP to everyone you follow and (b) the number of people with their own relay is very small, instead most users rely on some relay existing that will host everyone’s crap for free.

2024-11-17 21:03:49

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Making the assumption that every relay is going to see ~every post is very much not the same as assuming there will only be one relay. You’re just putting words in peoples’ mouths, then.

2024-11-17 21:02:45

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AFAIU you can have an App View that uses a relay, but could also be one software package. conceptually for the purposes of this discussion it’s really one thing.

2024-11-17 20:03:40

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But really I do not at all understand your comment here - literally the Bluesky devs encourage other relays to exist, and other people *do* run relays, just not very many because of the overhead. Suggesting that they view multiple relays as a bad thing is…. strange to me 🤷‍♂️

2024-11-17 19:58:44

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The comment about relay being an optimization was somewhat nitpicky, you’re just using the wrong term (technically the relay is a proxy between all the PDs’ and the app view, the app view stores all the posts too and you could drop the relay and replace it with the app view(s) connecting to all the PDSs directly).
The “App View” is a server that returns the posts to display in the feed to clients (eg the mobile app). In practice the App View is what *has* to have a full copy of all the tweets, much like a nostr relay works in practice today.
Clients simply making the same request to multiple App Views wouldn’t result in having to rewrite or throw anything away, I have no idea why you’re suggesting that - in general you’ll get the same response from each, just have to merge them on the client side.

2024-11-17 19:50:59

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How is this materially different for nostr relays? Sure, nostr clients connect to a few relays, improving censorship resistance greatly, but generally nostr relays are expected to have a large majority of all notes in the social context.

2024-11-17 04:29:39

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The ability for anyone to create a feed algorithm and share it directly as a post is the most obvious huge one. Decentralized opt-in moderation/spam filtering/tagging/NSFW-marking is the other.

2024-11-17 04:28:11

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Yea it perpetuates a movement, but articles talking about how there’s 1M users or whatever come after the 1M users….there was relatively little coverage between when they launched and a month or two ago, during which time they got 1M users. Blaming “the media” for losing users to competition is so lazy.

2024-11-17 04:26:28

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Yes, you’ve just explained nostr though?

2024-11-17 03:26:40

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But most of the articles are *about* how people are moving. You’re confusing cause and effect :)

2024-11-17 03:20:41

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I don’t think anyone is suggesting that Bluesky’s decentralization is here or substantial. It might be in the future, but it certainly isn’t now. The point is more that we should learn from their feature set, because they have some features that are very decentralizing of power within a social network, even though they run on centralized rails.

2024-11-17 03:18:31

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Why not? What’s fundamentally different about Bluesky’s architecture that makes it more expensive to run?