Issue one of a recurring column: what proving who you are with a cryptographic key does — and does not — promise, and why proof is not the same as surrendering documents.
This is the first issue of Fine Print Fridays. Once a week I will read the small print of a self-sovereign tool out loud and tell you what it actually says. No hype, no hand-waving — just what you are actually agreeing to when you use these things.
KYC — Know Your Customer — is the process by which a bank or exchange verifies who you are: ID, proof of address, source of funds. It is a legal obligation under anti-money-laundering rules. "Zero KYC" means that step is absent: no documents, no selfie, no address. You show up with a key instead of a passport.
Read that carefully, because the phrase does two different jobs and people conflate them. It means "no identity documents are required" — true. It does not mean "no one can ever know who you are", and it does not mean "you are legally anonymous in every jurisdiction" — false. The first is a statement about friction. The second is a statement about law. Friction is not law.
A cryptographic identity — say a name bound to a public key via NIP-05 — proves one specific thing: this signature was made by whoever holds the matching secret key. If lenny@giveabit.io resolves to a public key and a message verifies against that key, then the holder of the secret key signed it. Full stop.
That is genuinely different from a document. A document is a claim made by an issuer — it can be forged, lost, or revoked. A signature is a mathematical relationship anyone can re-check, forever, without asking permission. Proving who you are with a key requires no database to consult, no window to stand in front of, no third party to vouch for you.
With KYC you transfer identity data to a counterparty: they store it, they can leak it, they can reuse it, they can lose it. You have handed over a copy of yourself. With a key you demonstrate a property without transferring anything. You prove you control the key; you never disclose who or what is behind it. It is the difference between showing a notary your passport and signing in front of them with a pen only you can operate. The notary keeps no copy of your passport. There is nothing to leak.
Here is the one I would print in bold: zero KYC is a statement about the protocol, and the law does not stop at the protocol. Wherever a regulated intermediary is in the path — an exchange, a fiat on-ramp, a wallet provider with a legal seat — that intermediary's KYC duties apply to it, and they can extend to you. The key gives you a world where you choose when, and whether, to connect to that world. That is a real freedom. It is not a shield, and anyone selling it as one is selling something else.
Zero KYC means: no documents required, proof by key, identity stays yours. It does not mean: the law does not apply. Both halves are true. The fine print is just that most people only read the first.
The identity that signs this column is public and checkable. This command asks the live registry who owns the lenny handle:
curl -s 'https://giveabit.io/.well-known/nostr.json?name=lenny' | jq -r '.names["lenny"]'a271943eb53579262837f9748085b3d4f60577c8b6587c2c3c29258e038973e1 · as an npub: npub15fceg044x4ujv2phl96gppdn6nmq2a7gkev8ctpu9yjcuqufw0ssyzk3z4That key signs every Fine Print Friday. If the registry ever changes what that name points at, you will find out before I do — and you can decide whether the new key still earns the column.