Quantum test secures position with 75-meter accuracy over 2km

Researchers in China have demonstrated secure position verification with an accuracy exceeding 75 meters over a 2-kilometer distance. The work establishes a new protocol using quantum optics and relativity to address a fundamental limitation of classical positioning systems; these systems cannot guarantee a prover is truthfully reporting their location. This secure position-based authentication opens possibilities for applications ranging from financial transactions to disaster response and authenticated secure communications. The results establish secure position-based authentication as a practical possibility. A fundamental limitation of conventional positioning systems, the inability to guarantee a reported location is genuine, has been overcome in a new experiment demonstrating secure position verification over a…