When we say your key lives "in the chip", most people nod politely and picture some kind of black box. Fair enough — "cryptography" is one of those words that glazes eyes over. Here's the attempt to explain it without a single crypto word. With a vault and a mailbox.
The vault that hands nothing over
Picture your phone with a tiny vault built in — not symbolically, but literally a separate, sealed-off component on the board. Modern phones actually have this: Apple calls it the Secure Enclave, Google/Android StrongBox. At HIY we just call it the chip.
When you open HIY for the first time, that chip generates a key pair — two matching strings of numbers, one public, one secret. The secret one never leaves the chip. Not "stored encrypted", not "kept safely in a database" — it physically never leaves the chip. The chip can do things with it (sign, decrypt), but it never hands it to anyone, not even the app running on the same phone.
That's the difference from "the password is stored encrypted". An encrypted value can, with the right counter-key, be decrypted again — somewhere a path back to the plaintext exists. A value that never leaves the chip has no path back at all. There's nothing to steal, because there's no copy anywhere to steal.
The mailbox that can't read anything
Now to the relay — the server your messages pass through before they reach your friend. You'd think a server every message has to pass through is automatically a weak point. It is — if it can read along. Ours can't, and that's thanks to the vault above.
Before you and your friend can even write to each other, both your chips exchange the public halves of their key pairs — the half that's fine for anyone to see. From her public half and your secret half, a shared code can be computed that only the two of you know. The relay only sees the public halves during this exchange — that's like handing someone your postal address. Useful, but worthless on its own.
Every message that goes through the relay afterwards is encrypted with exactly that shared code. The server sees a data packet it can't open — it only knows where to forward it. That's the mailbox: it reliably carries the sealed envelope, but what's written inside is none of its business. Even if someone copied the entire server contents — mail folders, database, everything — it would stay unreadable data noise, because the code that would make it readable was never on the server.
Why this is more than a technical trick
The practical difference shows up exactly when something goes wrong — a hacked server, a government request, a dishonest employee. With a service that can read along, "will they hand over my messages?" is a question of trust and company policy. At HIY it's answered technically: there's nothing readable to hand over. You can't force someone to show you something they can't see themselves.
That doesn't mean HIY is immune to everything — whoever gets hold of your unlocked phone gets your chats, same as with any app. The chip protects the transport path and the messages along the way, not the device in your hand. That's a different threat with a different solution (screen lock, device encryption), and we don't want to sell the chip as a cure-all it isn't.
The catch we're not hiding
A chip that hands nothing over can't hand anything back to you either. Lose your phone without having set up recovery beforehand, and you lose the key too — permanently, not "call support and they'll restore it". That's exactly what our own article on what you get back and what you don't is about. No formulas, no "end-to-end" as a buzzword with nothing behind it — just a vault that hands nothing over, and a mailbox that can't read anything. Technically, there's nothing more to it, even if it sounds fancier when you use the right words.