Optimized decoy state QKD for underwater free space communication

Abstract

Quantum cryptography (QC) is envisioned as a solution for global key distribution through fiber optic, free space and underwater optical communication due to its unconditional security. In view of this, this paper investigates underwater free space quantum key distribution (QKD) model for enhanced transmission distance, secret key rates and security. It is reported that secure underwater free space QKD is feasible in the clearest ocean water with the sifted key rates up to 207[Formula: see text]kbps. This paper extends this work by testing performance of optimized decoy state QKD protocol with underwater free space communication model. The attenuation of photons, quantum bit error rate and the sifted key generation rate of underwater quantum communication is obtained with vector radiative transfer theory and Monte Carlo method. It is observed from the simulations that optimized decoy state QKD evidently enhances the underwater secret key transmission distance as well as secret key rates.

Performance analysis of decoy state quantum key distribution over underwater turbulence channels

“…The decoy QKD protocols were earlier studied for atmospheric, fiber and satellite links [17]- [19], however those results are not directly applicable to underwater environments with different channel characteristics. There have been only some sporadic efforts on investigating the performance of underwater decoy state BB84 QKD [20]- [24]. Specifically, in [20], an underwater quantum channel model was developed based on Monte Carlo simulations and some preliminary analysis on QBER and secret key rate (SKR) were presented.…”

Experimental Demonstration of Underwater Decoy-state Quantum Key Distribution with All-optical Transmission

“…Following the first BB84 protocol [1], QKD has been implemented in optical fiber [2][3][4] and atmosphere [5][6][7], leaving underwater quantum key distribution (UWQKD) a last barrier to conquer. In recent years, UWQKD has been studied theoretically [8][9][10] and experimentally [11][12][13][14][15][16][17]. Most of the experimental studies remain on the level of feasibility research of UWQKD.…”

Multi-hop quantum key distribution with passive relays over underwater turbulence channels

“…In particular, the quantum bit error rate (QBER) and secret key rate (SKR) of well-known BB84 protocol were studied in [8], [14]. The performance of other QKD protocols such as entanglement [13] and decoy state [6] were further investigated in underwater environments. In addition to these theoretical and simulation studies, experimental works were also conducted to demonstrate the feasibility of underwater QKD [7], [10]- [12].…”