Varun Raghunathan

Twin Field Quantum key Distribution (TF-QKD) is an promising quantum cryptography technique as it provides better secret key capacity than the fundamental limit of repeater-less transmission (i.e. PLOB bound) and extends the achievable communication distance. The key generation in TF QKD is based on selection of aligned phase slices, thereby taking a hit in the secret key rate as the inverse of the number of phase slices. Here we describe a technique for enhancing the probability of choosing phase slice by using a 4x4 port detection network with four detectors, which increases the key rate and also provides a way of detecting photon number splitting (PNS) attack.