The chip does not hand the key back.

A private key is a secret number. Whoever has it can sign for the cryptocurrency that number controls. Laptops are good at many jobs and poor at keeping one number away from everything else they run. Novubase exists so that number can be born somewhere smaller.

During setup the security chip draws the key itself. The drawing uses the chip’s own generator. Nothing on the computer types the key in, and nothing on the computer is given the key afterward. The reader application can prepare a request — a destination, an amount, a network path — and pass that request down the cable. The answer that comes back, if you press the right button, is a signature. A signature is evidence the chip agreed. It is not the key.

That split is the whole product. People sometimes describe a hardware wallet as a vault you open. The closer picture is a clerk who will sign a paper you can read and who will not let you borrow the stamp. The round screen is the paper. The buttons are how you tell the clerk yes or no.

The chip also keeps the paths it knows. Novubase derives keys for Bitcoin and for Ethereum, and for networks that use those same published paths. Adding a path is a firmware concern for the company. It is not a setting that copies the master key into a browser profile.

If the device is destroyed, the chip is gone and so is the copy of the key that lived on it. The paper phrase from setup is the other copy, and it is the owner’s. Restoring means writing that phrase into a new Novubase, on that device’s screen, not into a form on novubase.com. The site does not have a field for those words, and it will not grow one.

Related: why the screen has to be local, and the parts of the object.