Spectral-temporal-polarization encoding of photons for multi-user secure quantum communication
Eric S. Donkor · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2014
We describe a Quantum Key Distribution protocol that combines temporal-, spectraland polarization-encoding of photons for secure communication over an interconnected network of users. Temporal encoding is used to identify a user’s location or address on the network. Polarization encoding is used to generate private cryptographic key. Polarization encoded information is locally and randomly generated by users and exchanged only over a dedicated secure channel. Spectral encoding allows for the detection of eavesdropping and tampering by a malicious agent. Temporal-spectral signals sent from the network administrator (Alice) to a user are bright light source. On the other hand spectral-temporal signal from a network user (Bob) to the administrator (Alice) are single photons. Signals are sent across the network as ordered light pairs. The ordering format is randomly chosen and are revealed only at the time of key selection between the parties so that a secure one-time cryptographic pad can be generated