Quantum-secured device-independent global positioning system

Abstract We propose a device-independent quantum GPS protocol that employs multipartite Bell nonlocality to self-test a $[[5,1,3]]$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>[</mml:mo> <mml:mo>[</mml:mo> <mml:mn>5</mml:mn> <mml:mo>,</mml:mo> <mml:mn>1</mml:mn> <mml:mo>,</mml:mo> <mml:mn>3</mml:mn> <mml:mo>]</mml:mo> <mml:mo>]</mml:mo> </mml:math> five-qubit entangled state distributed to four satellites and one ground station, providing robust security against cyberattacks. Leveraging quantum rigidity, the protocol removes reliance on device assumptions, thereby bolstering GPS resilience. In the NISQ era, we compare superconducting (98.4% fidelity, 216 ns gate time) and trapped-ion (99.8% fidelity, 483 μs gate time) platforms for five-qubit code generation, and analyze photonic distribution over 20,200 km with $0.1\text{ dB}/\text{km}$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mn>0.1</mml:mn> <mml:mtext> dB</mml:mtext> <mml:mo>/</mml:mo> <mml:mtext>km</mml:mtext> </mml:math> attenuation, underscoring the necessity of LEO constellations or quantum repeaters for a scalable quantum GPS protocol.