Chapter2 1 2. Recent Progress in the Quantum-to-the-Home Networks

Abstract For secure data transmission to the end users in a conventional fiber-to-the-home (FTTH) network, quantum cryptography (QC) is getting much consideration nowadays. QC or more specifically quantum key distribution (QKD) promises unconditionally secure protocol, the Holy Grail of communication and information security that is based on the fundamental laws of quantum physics. In this chapter, we discuss the design issues in a hybrid quantum-classical communication network, performance of the cost-effective off-the-shelf telecommunication equipment, our latest results on a four-state (Quadrature Phase Shift Keying, ‘QPSK’) RF sub-carrier assisted continuous-variable quantum key distribution (CV-QKD) multiuser network based on ultra-low loss quantum channel (pure silica core fiber, ‘PSCF’) and microelectromechanical systems (MEMS) based add/drop switch. The results are thoroughly compared with the commercially available high-cost encryption modules. It is expected that the discussed cost-effective and energy efficient QKD network can facilitate the practical applications of the CV-QKD protocol on the commercial scale in near future for smart access networks.