<- Virtual Exhibitions in Informatics

Quantum Money

The roots of Quantum Cryptography date back to the late 1960s, when Stephen Wiesner a graduate Student at Columbia University tried to publish his idea of a quantum money which should be impossible to counterfeit. Wiesner’s concept was so revolutionary, that hardly anybody understood the great potential for further developments and therefore he didn’t get any support to do more research on this topic or even publish his ideas in some scientific magazine.

In Stephen Wiesner’s mind, every dollar bill should contain 20 light traps, small devices that should catch one photon each. Each note could also be identified by a unique serial number.
The light traps should be filled with 20 randomly polarized photons which can only be read out and restored by the bank that knows, what exact sequence of polarized filters needs to be used by reading the serial number.
Wiesner’s concept was brilliant but until today no one ever succeeded in building robust photon traps, so his concept seemed to be useless fiction.

Sketch of Stephen Wiesner's Quantum Money