The Coldcard RNG failure is a reminder that entropy is the most overlooked part of Bitcoin self-custody. I've just updated my interactive explainer on entropy and mnemonic seeds to cover what happened:

How secure is your Bitcoin wallet

What makes your Bitcoin wallet

If you're affected by this issue, secure your funds first - don't wait.

If you're in the UK, you can't buy bitcoin on a centralised exchange until you pass a test. The FCA calls this an "appropriateness assessment", and it’s supposed to prove you understand how risky and volatile it all is. This is a routine bit of friction that UK stackers will be familiar with. But last week a thought struck me: what if they made you pass a test before opening an ordinary fiat bank account? Prove you understand where your money actually goes, who legally owns it, and how much of it is really protected? So I built it! Ironically I expect only bitcoiners will be able to pass it.

The fiat banking knowledge test: an FCA thought experiment

Before you can buy Bitcoin in the UK, the FCA makes you pass a knowledge test on its dangers. So what would that test look like if the same standar...

Just published an interactive explainer on the Lightning network ⚡️ It includes a liquidity routing puzzle, which I think is a fun way to grasp the channel liquidity concept.

How the Lightning Network actually works

Lightning settles millions of payments without touching the blockchain. Interactive diagrams explain payment channels, multi-hop routing, and the l...

As always, comments and shares appreciated. Keep stacking. #bitcoin #lightning

Just published my explainer + tutorial on Silent Payments (BIP-352):

Silent Payments: a hands-on guide to better Bitcoin privacy

A hands-on guide to Silent Payments: set up a reusable, private Bitcoin address in Sparrow, understand the scanning key, and see how BIP-352 really...

Publish one reusable `sp1` address and share it anywhere, yet every payment lands on a different on-chain address, with no public link between them. No XPUB, no sender interaction. Sparrow + a Frigate server makes it practical to set up and test today, even without running your own node. #bitcoin #privacy

Been working on this a long time:

What is Bitcoin and how does it work?

A first-principles introduction to Bitcoin. Interactive diagrams explain the double-spend problem, hashing, mining, keys, transactions, and fixed s...

It’s a first-principles explainer of Bitcoin, with interactive demos throughout. Incorporates much of what I’ve built this past year. Feedback / suggestions appreciated 🙏

I’ve built an interactive explainer for Bitcoin mining - it walks through hashing, proof-of-work, and the difficulty adjustment from first principles. Enjoy!

Proof of work: what Bitcoin mining really does

What do Bitcoin miners actually do? An interactive exploration of hashing, difficulty adjustment, and why proof of work makes Bitcoin sound money.

Interactive explainer of HD wallets, derivation paths, and bitcoin addresses

Hierarchical determinism: how Bitcoin

A visual, practical walkthrough of how your recovery phrase becomes real Bitcoin addresses.