Every person who has ever managed self-custodial cryptocurrency knows the physical ritual of the high-stakes broadcast. Your palms sweat slightly as you copy a 42-character hexadecimal string from one window to another. You lean toward the monitor and read the first four characters, then the last four characters, and then, because the transfer is large enough to hurt, you force yourself to read the middle 34 characters out loud. You press the physical confirmation button on your hardware signer, broadcast the transaction, and spend the next two minutes staring at a block explorer in dead silence, waiting for the balance to appear on the other side.

When I describe this ritual to former colleagues from my 25 years in commercial banking,…