Quantum Key Distribution with Polarization-Entangled Multiphotons
Yu‐Hui Luo · AIP conference proceedings · 2004
Multiphoton entanglement in the same polarization has been theoretically shown to be obtainable by type‐I spontaneous parametric down‐conversion (SPDC), which can generate bright pulses more easily than type‐II SPDC. A new quantum cryptographic protocol utilizing polarization pairs with the detected type‐I entangled multiphotons is proposed as quantum key distribution. The information capacity versus photon number corresponding to polarization is calculated after considering the transmission loss inside the optical fiber, the detector efficiency and intercept‐resend attacks under the level of channel error. This result thus achieved compares very favorably with all other schemes employing entanglement.