Abstract With increasing demands for secure high-speed wireless communications, integration of quantum key distribution (QKD) into light fidelity (LiFi) systems is a promising method for boosting data confidentiality in optical wireless networks. The BB84 protocol and Mach–Zehnder modulator (MZM) are utilized with a pump-assisted continuous wave laser at 1,550 nm and polarization control components to encode quantum states onto photons. They are transmitted on free space optical (FSO) links with a length ranging from 2 km to 8 km and received using Avalanche photodiodes (APDs) and optical filters. Performance analysis conducted using bit error rate (BER) and Q-factor analysis. BER maintained at zero across all tested configuration and transmission distance up to 8 km indicating excellent signal integrity and security. A highest Q-factor achieved a maximum of 3,055.9, which ensures signal integrity and low interference noise. The system operates at a simulated data rate of 10 Gbps, suitable for high speed optical wireless communication. Consistently high eye height (∼172,210 units) and stable decision thresholds confirm minimal inter-symbol interference and accurate symbol recognition. And the Poincaré sphere showed even polarization stability for different optical power levels. This work presents a simulation-based implementation of a polarization encoded QKD system over a LiFi-enabled FSO communication channel, aiming to enhance secure optical wireless communication. Calculated based on quantum bit error rate (QBER) and included in the theoretical analysis to demonstrate practical secure throughput.
Abstract With increasing demands for secure high-speed wireless communications, integration of quantum key distribution (QKD) into light fidelity (LiFi) systems is a promising method for boosting data confidentiality in optical wireless networks. The BB84 protocol and Mach–Zehnder modulator (MZM) are utilized with a pump-assisted continuous wave laser at 1,550 nm and polarization control components to encode quantum states onto photons. They are transmitted on free space optical (FSO) links with a length ranging from 2 km to 8 km and received using Avalanche photodiodes (APDs) and optical filters. Performance analysis conducted using bit error rate (BER) and Q-factor analysis. BER maintained at zero across all tested configuration and transmission distance up to 8 km indicating excellent signal integrity and security. A highest Q-factor achieved a maximum of 3,055.9, which ensures signal integrity and low interference noise. The system operates at a simulated data rate of 10 Gbps, suitable for high speed optical wireless communication. Consistently high eye height (∼172,210 units) and stable decision thresholds confirm minimal inter-symbol interference and accurate symbol recognition. And the Poincaré sphere showed even polarization stability for different optical power levels. This work presents a simulation-based implementation of a polarization encoded QKD system over a LiFi-enabled FSO communication channel, aiming to enhance secure optical wireless communication. Calculated based on quantum bit error rate (QBER) and included in the theoretical analysis to demonstrate practical secure throughput.
Abstract Quantum key distribution (QKD) is a process that utilizes the principles of quantum mechanics to securely share a secret key between two parties, ensuring unconditional security. Diverse QKD protocols are established to guarantee the security and integrity of information against any attempts by an eavesdropper monitoring the transferred photons. One of these protocols is the six-state protocol. This work employs OptiSystem 21.1 simulation software to design and emulate the six-state protocol, wherein polarization states are produced through random switching control rather than optical modulators. The protocol’s performance, indicated by quantum bit error rate and secure key rate, is analytically examined for both free space optical (FSO) channel and optical fiber channel, incorporating parameters from two types of commercial single-photon detectors to enhance realism. The maximum secure key rate attains 5.439 Mbps at 10 km of optical fiber, in contrast to 1.674 Mbps at 0.2 km under clear weather conditions in the FSO quantum channel utilizing ID 281 single-photon detector modules across both channels. The maximum distance that guarantees secure key rate with ID 281 for FSO channel is 2 km with 1760 bps with heavy haze compared to 100 km optical fiber with secure key rate of 15,000 bps.
Quantum Key Distribution (QKD) is a potential defense against future quantum attacks that can break traditional encryption algorithms, such as RSA and ECC. The current work is based on the development of the BB84 protocol with the features of utilizing quantum mechanics and eavesdropping detection through signal disturbance. A simulation of the BB84 protocol was built using polarization encoding over a 10 km single-mode optical fiber using OptiSystem software. The system consists of standard telecom equipment, such as a continuous wave laser at a frequency of 193.1 THz, polarization controllers, and single-photon detectors. Both secure and insecure cases were simulated, where an attacker (Eve) had used an intercept-resend attack. The outcome showed significant Bit Error Rate (BER) and Quantum Bit Error Rate (QBER) increases during attacks, thus proving the protocol's vulnerability to interference. In addition, a special intrusion detection system based on BER was used to identify such anomalies in real-time. The simulation illustrates the feasibility of using QKD in today's optical networks to secure communications.
In response to the increasing demands for reliable, fast, and secure communications beyond 5G scenarios, the high-capacity networks have become a focal point. Quantum communication is at the forefront of this research, offering unmatched throughput and security. A free space optics (FSO) communication system integrated with fiber-end is designed and investigated using the Bennett–Brassard 1984 quantum key distribution (BB84-QKD) protocol. Simulation results show that reliable transmission can be achieved over a 10–15 km fiber length with a signal power of −19.54 dBm and high optical-to-signal noise of 72.28–95.30 dB over a 550 m FSO range under clear air, haze, fog, and rain conditions at a data rate of 1 Gbps. Also, the system using rectilinearly and circularly polarized signals exhibits a Stokes parameter intensity of −4.69 to −35.65 dBm and −7.7 to −35.66 dBm Stokes parameter intensity, respectively, over 100–700 m FSO range under diverse weather conditions. Likewise, for the same scenario, an FSO range of 100 m incorporating 2.5–4 mrad beam divergence provides the Stokes power intensity of −6.03 to −11.1 dBm and −9.04 to −14.12 dBm for rectilinearly and circularly polarized signals, respectively. Moreover, compared to existing works, this work allows faithful and secure signal transmission in free space, considering FSO–fiber link losses.
In the fast-paced world of digital communication, the need for secure and efficient data transmission is growing. For the growing need to integrate Quantum Key Distribution and Light Fidelity technologies to revolutionize information transfer, we propose an innovative framework that combines end-to-end quantum encryption with high-speed optical data transfer via Li-Fi, using polarized photons as bitwise data carriers. There are two components of the proposition, the hardware and the software. The hardware components facilitate the encoding, transmission, and reception of data. Software aspects involve using Arduino IDE for programming secure communication protocols, and encoding algorithms, and ensuring synchronization and the usage of Quantum Toolbox in Python for simulating the BB84 quantum algorithms and error rate analysis. Testing involves unit testing of individual components, integration testing of the complete system, and performance evaluation of Li-Fi communication speed and QKD security. The simulation converts each bit of data into a virtual photon, passing it through polarizers, and receiving it with potential bit alterations. Router R1 and Router R2 handle photon initialization, error checking, secure key establishment, and final message transmission and decryption. The integration of a Li-Fi prototype evaluates data transfer efficiency. Router R1 begins by encoding data into virtual photons and generating a secure encryption key. Router R2 receives these photons, decodes them, and verifies and decrypts the data using the secure key. The iterative process of sending, receiving, confirming, and error-checking between Router R1 and Router R2 is essential for preserving data integrity. Our results demonstrate the effective application of quantum encryption and optical data transmission, providing a scalable, secure, and efficient solution for contemporary digital communication networks.
The purpose of this research is to analyze and explore quantum theorems as a wireless telecommunications security solution in the future. This study uses a quantitative approach through simulation and performance analysis of QKD systems in wireless channels, by combining literature studies and comparative analysis between QKD and PQC. Meanwhile, the wireless communication simulation model, using the QKD protocol and PQC algorithm, with Free Space Optics (FSO), WiFi, and LiFi-based network scenarios. The simulation was carried out using MATLAB. This study is based on QKD, which uses BB84 and CV-QKD protocols on FSO 100m and LiFi wireless channels. And based on PQC, which uses the Kyber algorithm, with AES authentication for communication. Both models were simulated and tested based on the parameters of Quantum Bit Error Rate, Key Generation Rate, latency, and resistance to third-party attacks (wiretapping detection). Furthermore, the analysis was carried out quantitatively and comparatively to compare the performance of QKD and PQC based on the QBER, latency, KGR, and wiretapping detection of implementation. This analysis are combined with data based on the literature, to formulate optimal implementation strategies in the context of future wireless networks. The results indicate that QKD, specifically CV-QKD, has significant potential for use in attack-sensitive wireless communications, such as military, government, and industrial applications. However, this model requires more complex hardware and infrastructure investments in its implementation. Meanwhile, PQC offers a more ready-to-use and cost-effective solution for everyday communications that remains resilient to quantum attacks.
Current Free-Space Optical Quantum Key Distribution (FSO-QKD) systems are mainly focusing on the development of critical components needed towards the realization of satellite-based QKD, relying on bulky optical telescopes equipped with expensive optical systems. The cost and complexity of these systems hinder the establishment of a practical FSO-QKD infrastructure deployed as the wireless last-mile segment of Quantum Communication Infrastructure for applications in urban environments. In this work, we experimentally demonstrate successful transmission of polarization encoded qubits over 0.5 km free space metropolitan link with enhanced noise suppression for both nighttime and daylight operation. Βy deploying two low-cost, Single Mode Fiber-coupled, optical terminals along with a prototype quantum sender station operating in C-band, Quantum Bit Error Rate (QBER) values below 3.5% were achieved, with expected Secure Key Rates up to 1 kbps during nighttime. The FSO link was integrated with existing in-building fiber infrastructure, demonstrating stable operation and acceptable QBER values below 5.5%, even when coexisting with intense C-band light signals (> 10 mW) propagating alongside the photonic qubits. The field trial and its comprehensive verification paves the way for practical FSO-QKD in city-scale environments, enabling end users to share quantum keys over kilometer-scale wireless links between building rooftops in last-mile connectivity scenarios.