Analysis of Herladed Single Photon Decoy State Protocol Using Single Photon Detectors for Quantum Secure Imaging

Spontaneous parametric down-conversion heralded single photon pairs (HSPS) are utilized in quantum key distribution (QKD) and quantum imaging (QI) experiments. Decoy state methods enhance security in these fields. HSPS is well-suited for integrating QKD protocols, reducing measurement uncertainty, and ensuring secure quantum imaging. This study examines the performance of the HSPS-decoy state method for quantum imaging under various conditions, focusing on secure key rate and Quantum Bit Error Rate (QBER) for free space applications. We specifically investigate the HSPS within the BB84 decoy state protocol for secure quantum imaging in free space. The dark count rate significantly impacts QBER, affecting the maximum tolerable loss. Low-efficiency, low-noise detectors can outperform high-efficiency, high-noise detectors, highlighting the importance of minimizing dark counts for optimal system performance.