Practical Source Security of On-chip Continuous Variable Measurement Device Independent Quantum Key Distribution

In the evolving field of Continuous Variable Quantum Key Distribution (CV-QKD), notable for its synergistic potential with existing optical communication infrastructures, a high channel capacity, and an anticipated surge in secret rates, the Measurement Device Independent (MDI) framework stands as a bulwark against side-channel vulnerabilities at the measurement juncture [1] –[4]. Recent years have witnessed quantum photonics technology leapfrogging into a realm that promises the realization of fully integrated CV-MDI-QKD transmitter terminals, a cornerstone for large-scale CV-MDI-QKD networks. However, integrating high-efficiency on-chip light sources while effectively navigating the treacherous waters of practical security challenges remains a formidable task [5], [6]. This study is pioneering in its focus on the practical security intricacies stemming from imperfections in on-chip light sources within CV-MDI-QKD systems. We propose defense mechanisms tailored to shield against the risks associated with source defects, thereby laying a robust foundation for secure, reliable on-chip CV-MDI-QKD transmission terminals. This advancement is a critical enabler for the widespread adoption of CV-MDI-QKD, signaling a paradigm shift in secure communications.