Quantum money

A quantum money scheme is a quantum cryptographic protocol that creates and verifies banknotes that are resistant to forgery. It is based on the principle that quantum states cannot be perfectly duplicated (the no-cloning theorem), making it impossible to forge quantum money by including quantum systems in its design.

The concept was first proposed by Stephen Wiesner circa 1970 (though it remained unpublished until 1983), and later influenced the development of quantum key distribution protocols used in quantum cryptography.