Quantum counterfeiters might succeed
Money encoded by photons should be secure, but physicists find loophole
QUANTUM CASH Physicists have created quantum money by encoding data with light. The researchers transmitted a quantum version (right) of a real bill, an old Austrian banknote (left). Each grayscale shade in the quantum bill corresponds to a different photon polarization.
K. Bartkiewicz et al/npj Quantum Information 2017