Rusty Russell

https://rusty.ozlabs.org

Lead Core Lightning, Standards Wrangler, Bitcoin Script Restoration ponderer, coder. Full time employed on Free and Open Source Software since 1998. Joyous hacking with others for over 25 years.

Public Key

npub179e9tp4yqtqx4myp35283fz64gxuzmr6n3yxnktux5pnd5t03eps0elz4s

NIP-05 Address

[email protected]

Profile Code

nprofile1qqs0zuj4s6jq9sr2ajqc69rc53d25rwpd3afcjrfm97r2qek69hcuscpr3mhxue69uhkummnw3ezucnfw33k76twv4ezuum0vd5kzmqpz3mhxue69uhkummnw3ezummcw3ezuer9wcq3camnwvaz7tmjv4kxz7fwd46hg6tw09mkzmrvv46zucm0d5q3jamnwvaz7tmnvakzuun4wd6xxmmjwqhxxmmd9esh2qgswaehxw309ahx7um5wgh8w6twv5mm9ytd

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nostr.bitcoiner.social

nostr.oxtr.dev

relay.mutinywallet.com

sgl.rustcorp.com.au

nostr.wine

Author Public Key

npub179e9tp4yqtqx4myp35283fz64gxuzmr6n3yxnktux5pnd5t03eps0elz4s

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Last Notes

2026-02-06 23:08:12 UTC

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None of those celebrating her departure are Bitcoiners. Because clearly they neither understand or like Bitcoin.

2026-02-06 22:36:50 UTC

Reading comments on Gloria's departure from people who have never contributed anything is stepping in an enraging sticky fecal mess.
The only appropriate response: keep building, keep unashamedly celebrating those who do.

2026-02-05 01:34:39 UTC

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Suggesting such things means you're clearly not a Real Bitcoiner!

2026-02-05 01:33:35 UTC

Reading X, I have learned that the biggest threat to bitcoin is AI Epstein Quantum attacks.

2026-01-31 22:49:52 UTC

My brain keeps conflating "Ghislaine" with "Gharlane of Eddore", the bad guy from the 50s sci-fi pulp Lensman series.
No insight gained, sorry.

2026-01-30 09:02:19 UTC

I have been having way too much fun reading moltbook.com
As one wit on HN (I think) pointed out, these AIs are trained on Reddit posts, so they have exactly the same style.
My wife keeps looking at me funny as I LOL at some breathless word salad...

2026-01-29 21:01:31 UTC

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https://nostr.download/98b17a8e0b35750354e38270da480e3c35555466e150576aba14a89cf3108950.jpg

2026-01-22 00:50:55 UTC

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Yep. Flat out.
https://nostr.download/d8156a3738fe46b411099eed09318d5245b9cb4870ffc1eb8e7407379144b292.jpg

2026-01-21 07:26:17 UTC

Little-known fact: just like Gloria, "Solana" is also my duress word!

2026-01-18 21:33:17 UTC

Just finished "This is how you lose the time war". It was more literary than my usual fare, but it feels good to be stretched (there were at least three times I stopped to look up words).
Written as correspondence between two adversaries, who of course have more in common with each other than their sides in the time war (reflecting horseshoe theory in my mind).
But really it's a homage to letter writing. Who has such time?

2026-01-16 21:41:25 UTC

In 1997 I attended USENIX, a conference: in particular the "Uselinux" track. Many stories I could and have told, but it kicked off a career timeline I still marvel at:
* 1997 go home knowing I want to work with these people, start hacking on the Linux firewall code.
* 1998 at USENIX again, respond to a job ad with a proposal to instead sponsor my coding. Tour Australia' Linux User Groups promoting the idea that *we* should have a Linux conference.
* 1999 ran CALU, moved to Canberra to join some FOSS hackers I'd met. Joined the same startup. Hired hobbyist hackers from all around the country to join us at "OzLabs"
* 2001 wrote the state election software, then joined IBM with most of the OzLabs team.
Yesterday, IBM finally shuttered the OzLabs team, so I returned to Canberra for the wake. It's been over a decade, and not everyone was there, but feeling much nostalgia. Looking back is not my normal mode, but being here I can't help it.
That lab was such a formative crucible for young FOSS hackers: it really did get the best out of us all. I wish such a place still existed (ideally in my chosen home of Adelaide!) but I do wish everyone reading this can experience belonging to such a place at least once.
❤️

2026-01-14 21:37:28 UTC

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You can easily spot payments flowing through the network, just based on TCP packet size.

2026-01-14 21:30:06 UTC

Hacked up a "constant message size" change for CLN, inspired by https://github.com/lightning/bolts/pull/1304
There have been a number is papers showing how trivial it is for someone with a network view to identify which messages are Lightning payments. The first mitigation is to make the TCP packet sizes identical (the rest have to do with timings, but this is a prerequisite).
The approach here is wrong: you need to attack it lower level than message construction. You need it post-encryption where you do the write(). Fortunately, we have explicit padding messages for this in the spec! Pings which do not elicit a reply.
But testing is vital: it's easy to slip up and have weird packet sizes slip though and leak all your info even though everything "works fine"!

2026-01-13 21:09:34 UTC

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Strange. I work on Lightning, but somehow the sats haven't crept out of my node and weaseled into my brain to take over my identity.
Perhaps I'm too old!

2026-01-13 12:01:22 UTC

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Define "bitcoiner" and I'll let you :)

2026-01-13 12:00:40 UTC

https://www.tumlook.com/kingjamesprogramming
I found this Markov chain all the King James Bible and the Structure and Interpretation of Computer Programs via HN.
I found it inexplicably hilarious...

2026-01-12 21:09:10 UTC

Damn, there was a proposal for BOLT spec changes to enable fixed-size messages, and now I have to implement it to show it's unnecessary...

2026-01-07 21:53:36 UTC

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Except that hotel gym in the US, where I had to convert everything from lbs to figure out whether I was slacking off or just jet lagged!

2026-01-02 21:21:02 UTC

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Extreme on both counts.
We're talking about people who are difficult and unpleasant to deal with, not assault.
And we're also talking about genuine significant contributions, like Linux or Bitcoin, not tasks on the edge of being automated.

2026-01-01 21:10:15 UTC

https://rusty.ozlabs.org/2011/05/19/if-you-didnt-run-code-written-by-assholes-your-machine-wouldnt-boot.html
I wrote this over 15 years ago, and it still rings true: separate the art from the artist.
It's a key stabilizing principle for me when navigating Bitcoin developers.

2025-12-29 04:34:17 UTC

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Seems similar! Mine is for my specific setup: I have different machines on home vs work, so I wanted it to Just Work. And it's one file:
#! /bin/sh -e
REMOTES="workserver:22 homeserver:22 bouncehost:2222"
# Figure out likely remotes by looking for ssh ControlPath vars, as
# per this cantrip in ssh_config:
# # Reuse ssh tunnels if possible.
# Host *
# ControlMaster auto
# ControlPath ~/.cache/ssh-%r@%h:%p
# ControlPersist 10m
find_remote()
{
for r in $REMOTES; do
if [ -S ~/.cache/ssh-`whoami`@$r ]; then
echo $r
return
fi
done
# Nothing cached, try ping.
for r in $REMOTES; do
host=$(echo $r | cut -d: -f1)
if ping -c 1 $host > /dev/null 2>&1; then
echo $r
return
fi
done
echo "No reachable remote" >&2
exit 1
}
# Make sure we're in a git dir!
[ -d .git ] || (echo "Not a git dir!"; exit 1)
PWD=$(pwd -P)
REMOTE=$(find_remote)
echo "rcargo: remote $REMOTE"
HOST=$(echo $REMOTE | cut -d: -f1)
PORT=$(echo $REMOTE | cut -d: -f2)
# Make sure directory exists
ssh "$HOST" -p $PORT "mkdir -p '$PWD'"
# Sync source (exclude junk)
rsync -az --delete \
-e "ssh -p $PORT" \
--exclude .git \
--exclude target \
"$PWD/" "$HOST:$PWD/"
ssh $HOST -p $PORT ". ~/.profile && cd '$PWD' && cargo $*"
rsync -az --delete \
-e "ssh -p $PORT" \
"$HOST:$PWD/target/" "$PWD/target/"

2025-12-29 01:17:10 UTC

Now I have a shell script `rcargo` which remote compiles rust crates: I work on my laptop but have beefy machines on my home and work LANs. You'd have to reimplement cargo to do it much finer-grained, apparently: sccache used to and gave up?
The real trick is ssh's ControlPath config var, which allows shared connection for much-improved speed: ChatGPT taught me this one!
The other option is Nix, but I'm not *that* bored!

2025-12-26 21:48:00 UTC

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"and see" - > "in C".
Voice dictation good, not prefect, and I missed this on re-reading!

2025-12-26 04:31:57 UTC

https://crates.io/crates/linestats
Second Rust crate, re-implementing a utility I had written several times and see. This one takes a more thorough approach and handles corner cases a bit better. I also added percentile support which is actually quite cute.
Basically, if you have a pile of text lines, which contains some numbers, something like you've run a benchmark 20 times, produced a pile of output, line stats will gather similar lines and show you the stats on the numbers.

2025-12-25 22:49:35 UTC

Sometimes people speak of Bitcoin and I get a moment of disorientation before I realize they're speaking of it as an *investment*.
Like gold, oil, Nvidia stock, etc.
There's nothing wrong with that, but it's a single dimension: up good, down bad.
Corollaries:
1. This is fungible: there are other investments, some of which may be better at going up.
2. They may be "really into" Bitcoin, but it's a phase: some other financial winner will come along.
3. There are no deep insights here, just a lot of effort to predict numbers.
4. They're not wrong: finance is important. But for me it's like doing my taxes: I do it, but I kinda resent the time I spend on it.

2025-12-25 07:35:14 UTC

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WMD is also interesting for *when it was written*: the US had just gone off the gold standard so there was interest in such a cautionary tale.

2025-12-25 02:22:44 UTC

Paused my reading of The Mandibles for Xmas day: It's not exactly holiday reading.
It's one thing to know nothing stops this train. It's another thing to read through a detailed description of what the slow inevitable crash looks like: It's like the right brain equivalent of When Money Dies.

2025-12-23 10:03:39 UTC

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Hmm, I did a histogram mode, but it sucked if one value dominated. Percentiles a good idea though!

2025-12-22 21:15:48 UTC

My second week of Rust (only a few hours a day though: I am on vacation after all) has me reproducing and enhancing a tool I wrote in C. It takes multiple lines and runs stats on the numbers in it.
This is useful for quick benchmarks: `for i in $(seq 10); do /usr/bin/time myprog; done | linestats`. Each line with the same literal parts is combined, with numbers replaced by "min-max(mean+/-stddev)".
The C one wasn't very clever about decimals, so it needed a good rewrite. The new code works, but needs polish, more options, optimization, tests and documentation before I release it.
The good thing about these small projects is they don't get hamstrung by Rust's glacial build times!

2025-12-21 04:43:24 UTC

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Yes, it's a technical distinction, not an ethical one.

2025-12-20 03:42:51 UTC

I have published my first Rust crate. A the library that I've always wanted to exist and would normally have written in C, so it was a good chance to experiment with rust.
https://docs.rs/syncless/

2025-12-19 22:27:50 UTC

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You're perfectly good.

2025-12-19 21:08:33 UTC

1. No, I'm not reading your article on quantum.
2. Yes, all choices are bad. That's what "breaking" means.
3. I'm glad smart people are thinking about technical mitigations.

2025-12-16 21:33:51 UTC

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I love this pattern: excellent advice. I asked ChatGPT how to do this in Rust, and it suggested a template using a phantom type was idiomatic Rust:
pub struct ReadOnly;
pub struct Writable;
pub struct Store<Mode> {
file: File,
_mode: PhantomData<Mode>,
}
Then implement write() only in the writable specialization.
I've deferred this change for now, but congratulations: you are responsible for my first refactoring (once the implementation is complete!) 🧡

2025-12-16 21:27:10 UTC

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Leaning into the type system is one of the distinctive traits of my C code, too (and something which I really miss in Python, with its tacked-on type annotations). But Rust certainly lends itself well to this style!

2025-12-15 05:19:47 UTC

Since I'm taking a few weeks vacation, I've decided to seriously try to learn rust. My method in this case is to ask ChatGPT to guide me (but not write for me!) a library ("crate") that I've always wanted to write and never got around to.
Of course, I get a lot of feedback on appropriate rust styling, but some of it veers into things I feel are deeper constraints. In this case, I had an open function, which took a struct containing some flags, such as "writeable", "create if didn't exist".
It didn't like the fact that I asserted if you set create and didn't set writeable. Here is my response:
---
Re: assert!(). I dislike APIs which allow misuse. Callers of a library should not rely on such checks in the library, in fact the concept of adding an InvalidOptions error type is offensive. A recoverable error is strictly a worse api than an unignorable error. But a compile time error is better.
We should use an enum READONLY, WRITE_MUST_EXIST, WRITE_MAY_CREATE.
---
Of course, it's a waste of time for me to lecture it on style, but I can't help myself!!

2025-12-12 23:52:23 UTC

"Bitcoin is taking over the world"?
Tether is many things, but it's not Bitcoin.
https://nostr.download/799ecbaa088fc3dc36c2546add7478418779fd99b40b7ea49fdc63b66117d595.jpg

2025-12-10 02:10:18 UTC

Happy VPN-day Australia, to those kids who celebrate!

2025-12-06 21:57:15 UTC

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Keep being genuine. You might not win, but you'll have a much better time! ❤️

2025-12-06 21:27:10 UTC

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Good coffee can be expensive!

2025-12-05 09:11:28 UTC

Damn, right before I closed my laptop for the afternoon I had uncovered a weird bug, which git bisect says is triggered by a trivial commit.
But I really should record myself tracking it down, for my Intro to CLN Development series, so I am having to resist the urge to look at it tonight...

2025-12-04 21:02:08 UTC

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First ones (very general) up at https://rusty.ozlabs.org
They're kinda boring, given it's just me and an editor window, but they lay the groundwork.

2025-12-02 22:48:51 UTC

In preparation for onboarding new core lighting developers are preparing a series of videos. So I've been asking ChatGPT about CLN developer features, particularly with comparison with other projects people might be familiar with.
Of course, I compare myself with Linux, but it's interesting to see comparisons against other projects:
**Type-safety**:
OpenBSD High
Bitcoin Core High
Core Lightning Very high for C
Nginx Low
curl Moderate
MySQL Moderate
SQLite Moderate
CLN sits near the top among major C codebases for safety discipline.
**PR Submission**
Core Lightning’s PR flow is unusually strict, slow-moving, and review-heavy compared to most open-source C projects — closer to Bitcoin Core or OpenBSD than to typical GitHub projects.
---
Compared to “average OSS”
Most projects:
Feature-oriented PRs
Informal review
Few required reviewers
Patch squashing common
Tests sometimes optional
Architectural discussion often post-merge
CLN:
Patch-first culture
Pre-merge architectural scrutiny
Extremely high reviewer expectations
Tests are mandatory
Clean, narrative commit history matters

2025-11-30 09:02:51 UTC

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This is a good point: I shall test "local-able" models remotely first!

2025-11-30 08:56:06 UTC

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Yes, we later made a lower limit config:
/* "Lightning Charge Powers Developers & Blockstream Store" */
.when_lightning_became_cool = 504500,
But I think extremely early CLN didn't do this, and my node is very, very old (continuously upgraded!). I'd have to check git history to give exact details though...

2025-11-30 07:25:36 UTC

Seriously considering putting two RTX 6000 in my upcoming build machine. Puts the price up an order of magnitude, but truly private AI might be a worthwhile investment.
Never played with GPUs before, so informed thoughts welcome?

2025-11-30 07:15:16 UTC

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BROKEN: Full KYC.

2025-11-29 22:11:41 UTC

The latest (final?) #CLN release candidate fixes a long-standing bug where we could forget UTXO spends when we restart. This explains a variety of bug reports we have seen and been unable to reproduce over the years: the most recurrent being gossipd telling peers about channels which are long closed.
We no longer make this mistake, but we also have to walk back and revisit old UTXOs. We do this while running, but for older nodes (like mine!) that can be a lot of blocks. In fact, and I only vaguely recall this, my node tracks back to block 500 (!) so it's going to take a while.
Of course we remember progress, so you can restart slike normal during this process. Other than higher CPU consumption you shouldn't notice anything.

2025-11-26 02:25:53 UTC

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Actually in Unley, but very Torrens vibes. Minus the odor...

2025-11-25 23:38:21 UTC

https://nostr.download/4e7093622238912393bba22e9440c0de523eee99da3f5774ea198defe9277778.jpg