Secure Optical Networks Based on Quantum Key Distribution and Weakly Trusted Repeaters
In this paper, the authors explore how recent technologies can improve the security of optical networks. In particular, they study how to use Quantum Key Distribution (QKD) in common optical network infrastructures and propose a method to overcome its distance limitations. QKD is the first technology offering information theoretic secret-key distribution that relies only on the fundamental principles of quantum physics. Point-to-point QKD devices have reached a mature industrial state; however, these devices are severely limited in distance, since signals at the quantum level (e.g. single photons) are highly affected by the losses in the communication channel and intermediate devices.