On the Security of an Optical Layer Encryption Using Coherent-based TF-QKD in Classical Optical Fiber Links

Twin-field quantum key distribution (TF-QKD) protocols have remained an enticing solution because it is able to overcome many of the limitations that are inherently found in QKD. However, the performance of this technology is still not adequate to be implemented for secure transmission of data. A variant of the TF-QKD protocol is Coherent-based Two Field QKD (CTF-QKD), which utilizes coherent states for both transmission and detections, is integratable with current infrastructure, and has similar performance to current classical optical communication systems. This proceeding is a continuation of the preliminary security analysis that was previously published in [1–2]. Key vulnerabilities in the current system are identified in simulation and guidelines to prevent an eavesdropper from obtaining data from a tapping attack. Finally, the practical security of the system is discussed and the challenges for an attacker to accomplish real-time decryption of data transmitted.