1.
He, Jiaxiang; Vallejo, Luis; Giddings, Roger Philip; Jin, Wei; Faruk, Md Saifuddin; Yi, Xingwen; Tang, Jianming
Experimental Demonstrations of Chaotic Digital Filter-Based Physical Layer Security in Converged Fibre-mmWave Access Networks Journal Article
In: Journal of Lightwave Technology, vol. 43, no. 18, pp. 8839–8848, 2025, (Publisher: IEEE).
Abstract | Links | BibTeX | Tags: Bit error rate, Frequency division multiplexing, Optical signals, Phase noise, Quantum key distribution, Single mode fibers
@article{he_experimental_2025,
title = {Experimental Demonstrations of Chaotic Digital Filter-Based Physical Layer Security in Converged Fibre-mmWave Access Networks},
author = {Jiaxiang He and Luis Vallejo and Roger Philip Giddings and Wei Jin and Md Saifuddin Faruk and Xingwen Yi and Jianming Tang},
url = {https://opg.optica.org/jlt/abstract.cfm?uri=jlt-43-18-8839},
year = {2025},
date = {2025-09-01},
urldate = {2025-10-08},
journal = {Journal of Lightwave Technology},
volume = {43},
number = {18},
pages = {8839–8848},
publisher = {IEEE},
abstract = {Secure data transmission is experimentally demonstrated in a 1.67 Gb/s seamlessly converged fibre–millimeter wave (mmWave) network using the authors’ newly proposed chaotic digital filter (CDF)-based physical layer security (PLS) technique. The CDF-based encryption/decryption operates by introducing noise-like, key-dependent phase variations to conventional filter impulse responses. Validation is performed in a seamlessly converged network comprising a 25 km standard single-mode fibre (SSMF) link and a 5 m 36 GHz mmWave wireless link, utilizing cost-effective photonic-based mmWave generation and envelope detector-based reception. Experimental results show that the demonstrated PLS technique allows the encrypted signals to continuously flow between the fibre and radio frequency (RF) domains. The PLS technique also supports simultaneous optical and radio frequency access with almost identical BER transmission performances, and power penalties of <1 dB. To gain an in-depth understanding of the measured results, the CDFs’ characteristics, including their chaotic nature, sensitivity to security keys and optimum CDF design parameters, are explored both theoretically and experimentally in detail. The optimum security key properties and CDF's filter lengths are identified, which are independent of the transmission media and major characteristics of the encrypted signals. The CDF-based PLS technique offers salient advantages of ‘security-by-design’, ‘openness-by-design’, ‘dynamic security at the traffic level’, and ‘universal network compatibility’.},
note = {Publisher: IEEE},
keywords = {Bit error rate, Frequency division multiplexing, Optical signals, Phase noise, Quantum key distribution, Single mode fibers},
pubstate = {published},
tppubtype = {article}
}
Secure data transmission is experimentally demonstrated in a 1.67 Gb/s seamlessly converged fibre–millimeter wave (mmWave) network using the authors’ newly proposed chaotic digital filter (CDF)-based physical layer security (PLS) technique. The CDF-based encryption/decryption operates by introducing noise-like, key-dependent phase variations to conventional filter impulse responses. Validation is performed in a seamlessly converged network comprising a 25 km standard single-mode fibre (SSMF) link and a 5 m 36 GHz mmWave wireless link, utilizing cost-effective photonic-based mmWave generation and envelope detector-based reception. Experimental results show that the demonstrated PLS technique allows the encrypted signals to continuously flow between the fibre and radio frequency (RF) domains. The PLS technique also supports simultaneous optical and radio frequency access with almost identical BER transmission performances, and power penalties of <1 dB. To gain an in-depth understanding of the measured results, the CDFs’ characteristics, including their chaotic nature, sensitivity to security keys and optimum CDF design parameters, are explored both theoretically and experimentally in detail. The optimum security key properties and CDF's filter lengths are identified, which are independent of the transmission media and major characteristics of the encrypted signals. The CDF-based PLS technique offers salient advantages of ‘security-by-design’, ‘openness-by-design’, ‘dynamic security at the traffic level’, and ‘universal network compatibility’.
2.
Wang, Dingzhao; Liu, Xin; Xu, Chao; Ng, Soon Xin; Hanzo, Lajos
Short-Block Polar-Coded Reverse and Direct Reconciliation in CV-QKD Journal Article
In: IEEE Open Journal of Vehicular Technology, vol. 6, pp. 2195–2209, 2025, ISSN: 2644-1330.
Abstract | Links | BibTeX | Tags: Complexity theory, Continuous-variable quantum key distribution (CV-QKD), Fading channels, Maximum likelihood decoding, multidimensional reconciliation, Parity check codes, polar code, Polar codes, Protection, Protocols, Quantum key distribution, secret key rate, Simulation, Wireless networks
@article{wang_short-block_2025,
title = {Short-Block Polar-Coded Reverse and Direct Reconciliation in CV-QKD},
author = {Dingzhao Wang and Xin Liu and Chao Xu and Soon Xin Ng and Lajos Hanzo},
url = {https://ieeexplore.ieee.org/abstract/document/11087626},
doi = {10.1109/OJVT.2025.3591417},
issn = {2644-1330},
year = {2025},
date = {2025-01-01},
urldate = {2025-10-08},
journal = {IEEE Open Journal of Vehicular Technology},
volume = {6},
pages = {2195–2209},
abstract = {Continuous-variable quantum key distribution (CV-QKD) is a promising technique of supporting quantum-safe wireless networks in the emerging 6 G era, mapping quantum information onto the amplitude or phase of electromagnetic waves. However, conventional CV-QKD reconciliation methods often assume ideal classical side-information channels, which is an unrealistic scenario in practical deployments. To address this critical challenge, we propose a novel protection scheme integrating Polar and low-density parity-check (LDPC) codes. Specifically, Polar codes safeguard quantum transmissions due to their superior performance for short block lengths, while LDPC codes robustly protect the classical side information exchanged over auxiliary classical channels. We further enhance the CV-QKD performance by harnessing a soft-decision Polar decoding method combined with protocols specifically tailored for reverse reconciliation (RR) and direct reconciliation (DR). In the RR scheme, conceived decoding complexity is strategically distributed: Polar decoding is performed by Alice, and LDPC decoding by Bob, hence significantly reducing the computational demands compared to traditional schemes where both decoding processes are invoked at a single node. Simulation results validate the effectiveness of our approach, demonstrating that Polar codes consistently outperform LDPC codes in quantum transmission scenarios having short block lengths under 512 bits. These findings emphasize the strong potential of Polar coding-assisted CV-QKD in achieving secure and efficient quantum-safe control information transmissions, paving the way for practical implementation in next-generation wireless networks.},
keywords = {Complexity theory, Continuous-variable quantum key distribution (CV-QKD), Fading channels, Maximum likelihood decoding, multidimensional reconciliation, Parity check codes, polar code, Polar codes, Protection, Protocols, Quantum key distribution, secret key rate, Simulation, Wireless networks},
pubstate = {published},
tppubtype = {article}
}
Continuous-variable quantum key distribution (CV-QKD) is a promising technique of supporting quantum-safe wireless networks in the emerging 6 G era, mapping quantum information onto the amplitude or phase of electromagnetic waves. However, conventional CV-QKD reconciliation methods often assume ideal classical side-information channels, which is an unrealistic scenario in practical deployments. To address this critical challenge, we propose a novel protection scheme integrating Polar and low-density parity-check (LDPC) codes. Specifically, Polar codes safeguard quantum transmissions due to their superior performance for short block lengths, while LDPC codes robustly protect the classical side information exchanged over auxiliary classical channels. We further enhance the CV-QKD performance by harnessing a soft-decision Polar decoding method combined with protocols specifically tailored for reverse reconciliation (RR) and direct reconciliation (DR). In the RR scheme, conceived decoding complexity is strategically distributed: Polar decoding is performed by Alice, and LDPC decoding by Bob, hence significantly reducing the computational demands compared to traditional schemes where both decoding processes are invoked at a single node. Simulation results validate the effectiveness of our approach, demonstrating that Polar codes consistently outperform LDPC codes in quantum transmission scenarios having short block lengths under 512 bits. These findings emphasize the strong potential of Polar coding-assisted CV-QKD in achieving secure and efficient quantum-safe control information transmissions, paving the way for practical implementation in next-generation wireless networks.