"We describe the use of quantum-mechanically entangled photons for sensing intrusions across a physical perimeter.
Our approach to intrusion detection uses the no-cloning principle of quantum information science as protection against an intruder's ability to spoof a sensor receiver using a 'classical' intercept-resend attack.
Moreover, we employ the correlated measurement outcomes from polarization-entangled photons to protect against 'quantum' intercept-resend attacks, i.e., attacks using quantum teleportation.
We explore the bounds on detection using quantum detection and estimation theory, and we experimentally demonstrate the underlying principle of entanglement-based detection using the visibility derived from polarization-correlation measurements.
© (2009) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE)."
Source: The Quantum Fence https://www.spiedigitallibrary.org/conference-proceedings-of-spie/7342/73420H/Sensing-intruders-using-entanglement-a-photonic-quantum-fence/10.1117/12.820221.short?SSO=1
