As a matter of mathematical and physics,
we already do exactly that whenever we cast a brick or print paper or ?:
In a quantum perspective anything we create is utterly unique.
What is necessary is a device by which we can verify that a 'coin' is exactly what it pretends to be. for gold coins there is an approximation.
Yes, this gets weird in microseconds. Imagine for a moment you could buy a 'scrying stone' which would decrypt the quantum appearance of a coin reflecting a specific laser light.
A "coin" would have a specification written on it that, under a specific light, reflection would yield a specific pattern through a 'standard' 'scrying stone'. True Magick.