OptoElectronics and Communications Conference and International Conference on Photonics in Switching and Computing (OECC/PSC)

End-to-End Amplitude Noise based Classical Key Generation and Distribution with FPGA-implemented Post-Processing

Yanwen Zhu, Yuang Li, Xu Zhang, Yi Huang, Huibin Zhang, Yixin Wang, Jie Zhang

Published Jun 29, 2025• 0 citations

Publisher

Abstract

The PLSKGD scheme based on E2E amplitude noise is proposed and implemented on FPGA for quantization, information reconciliation, and privacy amplification. An experimental KGR of 1.21 Gbps was achieved on a 120 km optical fiber link.

DOI: 10.23919/oecc/psc62146.2025.11110298

Related papers

Fiber-optic physical layer key generation and distribution based on the phase of the error vector in end-to-end systems

Yanwen Zhu, Yixin Wang, Y. Li +6 more

This paper proposes an end-to-end physical layer secure key generation and distribution (E2E-PLSKGD) scheme based on error vector phase (EVP) for fiber transmission systems. It addresses compatibility issues in existing PLSKGD caused by additional random sources or devices, as well as limitations in application scenarios and insufficient key generation rate (KGR) from amplitude or phase modulation of intensity-modulated signals. We introduce a position-enhanced transformer (PE-transformer) architecture with adaptive position coding (APC) for accurate E2E modeling in coherent optical systems. Leveraging the inherent high randomness of signal phase in fiber systems, legitimate parties use the PE-transformer to build E2E models via bidirectional transmission, compute error vectors, and extract EVP noise as key quantization sequences. Using data from new negotiation cycles and transfer learning (TL), local E2E source models are rapidly updated to target models, enhancing key security. Simulations show superior E2E modeling, with R-Square values >0.95, excellent waveform fitting, and consistent data distributions across distances. Pearson correlation coefficients (CC) of EVP sequences between legitimate parties exceed 0.8 across 50-80 km distances and -2 dBm to 4 dBm launch powers, indicating strong correlation. Experimental validation on a 120 km fiber system shows an EVP sequence correlation of 0.72, with real-time post-processing achieved via FPGA. At a 5G baud rate, error-free KGR reaches 0.8 Gbps. The proposed architecture enables precise E2E modeling, offering a new approach for dynamic, high-quality key generation and a potential method for AI-empowered fiber transmission security.

Optics ExpressJul 24, 20252 citations

FPGA Implementation of Post-Processing for Classical Secure Key Distribution in Fiber Networks

Ying Cao, Shuhang Chen, Liuming Zhang +2 more

Real-time post-processing for physical-layer secure key distribution in fiber networks is implemented on FPGA, with quantization, information reconciliation and privacy amplification modules, where a key generation rate of 11.7 Mbps is achieved.

Conference on Lasers and Electro-OpticsJan 1, 20220 citations

Efficient FPGA-Based Implementation of Quantum Key Distribution Post-Processing System

Lianye Liao, Shi‐Hai Sun

Quantum key distribution (QKD), based on quantum mechanics, enables unconditionally secure key exchange even against adversaries with unlimited computing power. As the core of QKD post-processing, information reconciliation (IR) and privacy amplification (PA) ensure key consistency and security by correcting errors and removing leaked information. With the trend toward miniaturized and chip-based QKD systems, post-processing modules require highly integrated designs. FPGAs offer an ideal solution due to their low cost, power efficiency, and flexibility. This paper presents an FPGA-based QKD post-processing architecture using a polar codes-based appending IR algorithm, achieving reconciliation efficiency better than 1.1 under Eµ≥ 0.06 and Rm= 4. A convolution-structured Toeplitz hash module is developed for PA, supporting 53.13 Mbps data rate and 26.45 Mbps key rate with RPA= 0.5. The complete system is implemented on a Xilinx XCKU040 FPGA. Experimental results show support for 176.58 Mbps input, 36.59 Mbps real-time processing, and 17.56 Mbps key output, demonstrating strong performance and engineering suitability. The design features high integration and portability, offering a practical hardware solution for efficient QKD post-processing.

IEEE International Conference on Electronics, Communications and Intelligent Science (ECIS)May 23, 20250 citations

End-to-End Learning-Driven Dual Independent Key Generation and Distribution for Optical Network Physical Layer Security

Yanwen Zhu, Yixin Wang, Yuang Li +6 more

To address the urgent demand for secure optical fiber communication, a novel dual independent key generation and distribution scheme for Optical Network Physical Layer Security is proposed for the first time. End-to-end (E2E) learning with a Transformer algorithm featuring adaptive positional encoding is introduced to accurately model coherent fiber transmission systems, achieving an R-squared value exceeding 0.95 for waveform fitting and data distribution. The error vector phase (EVP) and amplitude noise (AN) of the E2E system are utilized to comprehensively characterize channel uniqueness, reducing system reconstruction risks while serving as sources for highly random key sequences for legitimate parties. Key consistency stems from channel reciprocity and precise E2E modeling, with feasibility analyzed across diverse link conditions. Leveraging the fact that eavesdroppers cannot access the system's full lifecycle data, keys are extracted from outputs of transfer learning (TL)-updated E2E models to enhance security. Security analysis under various eavesdropping scenarios demonstrates resistance to attacks. Experimental results show that, with FPGA-implemented post-processing, error-free key distribution is achieved over 120 km SSMF at EVP and AN key rates of 306.74 Mbps and 521.82 Mbps, respectively.

Journal of Lightwave TechnologyJan 13, 20260 citations

Post-Processing Protocol for Physical-Layer Key Generation and Distribution in Fiber Networks

Adnan A. E. Hajomer, Liuming Zhang, Xuelin Yang +1 more

The unique and random physical-layer properties of optical fiber channels have been exploited for a simple and cost-effective secure key generation and distribution (SKGD). However, state-of-the-art SKGD approaches focused mainly on initial key extraction, while the post-processing protocol has to be explored to guarantee error-free operation, effective key generation rate (KGR) and high key secrecy. Here we propose a full post-processing protocol for SKGD in fiber networks. A lossy quantizer is optimized to achieve the trade-off between the KGR and key disagreement rate. The distributed source coding based information reconciliation is used to remove quantization errors. The privacy amplification is applied to improve the randomness and secrecy of the generated key using hashing functions. The post-processing protocol provides a SKGD solution of error-free, high randomness and high secrecy in fiber networks.

IEEE Photonics Technology LettersJun 23, 202019 citations

Implementation of 400 Gbps quantum noise stream cipher encryption for 1520 km fiber transmission using end-to-end deep learning

Yunhao Xie, Xinran Huang, Guozhi Xu +4 more

In the era of large models and big data, the security of optical fiber communication backbone networks has garnered significant attention. Quantum noise stream cipher (QNSC) stands as a crucial method for safeguarding the physical layer security of optical fiber communications, yet the current schemes lag behind the rate capabilities of existing 400G optical fiber backbone networks. In this paper, we introduce deep learning into QNSC and propose an end-to-end quantum noise stream cipher (E2E-QNSC) scheme, which encrypts 16 quadrature amplitude modulation (QAM) into E2E-65536QAM/QNSC. Our experiments successfully demonstrate secure optical communication with a single-channel rate of 400 Gbps, a total capacity of 8.4 Tbps, and a transmission distance of 1520 km. Even in the most extreme scenarios, the detection failure probability (DFP) of the scheme remains at an excellent level greater than 0.9999, proving the security of the approach. The experimental results presented herein represent the highest rate-distance product record of QNSC secure transmission systems, to the best of our knowledge.

Optics LettersMay 8, 20256 citations