摘要
针对城域网光纤通信数据传输中的安全需求,提出一种基于放大自发辐射(ASE)光的密钥隐藏与分发加密光通信系统。该系统每次随机产生一个密钥来对数据进行加密,并通过波分复用技术将密钥与数据信息同步发送给授权用户。利用动态密钥机制,降低长期密钥被量子计算破解的风险。所提系统可以在频域与时域中隐藏数据与密钥信息,确保未授权用户接收到的仅是类噪声信号,有效防范未授权访问。仿真验证结果表明,传输码率为5 Gbit/s的通断键控(OOK)信号在传输50 km后,授权用户在接收光功率为-10 dBm时能准确接收并解码信息,误码率低至2×10^(-7),而窃听者的误码率始终为0.5,证明了所提系统的保密性能。本研究为光子层安全提供了一种可行的解决思路,有助于提升数据传输的安全性和隐蔽性。
Objective In the era of rapidly advancing global informatization,information security has emerged as a critical challenge that demands immediate attention.Conventional encryption technologies at the upper layers have proven inadequate in providing comprehensive protection against sophisticated eavesdropping threats,particularly in mission-critical sectors such as national defense,government operations,and financial systems.The imperative to ensure secure signal transmission at the physical layer has become paramount,as it serves as the fundamental safeguard for protecting sensitive data against increasingly sophisticated cyber threats.To enhance the security performance of optical communication systems,we propose a key concealment and distribution encryption optical communication system based on amplified spontaneous emission(ASE)light.Leveraging the broad bandwidth and high-noise characteristics of ASE light sources integrated with dynamic key encryption technology,a unique one-time key is generated for phase-based signal encryption in each data transmission.This approach not only effectively conceals the data and key signals but also enhances the system’s resistance to decryption by immediately updating dynamic keys.Simulation results demonstrate that an on-off keying(OOK)signal with a transmission rate of 5 Gbit/s,after transmitting 50 km,can be accurately received and decoded by authorized users at a received optical power of-10 dBm,with a bit error rate(BER)as low as 2×10-7.In contrast,the eavesdropper’s BER remains consistently at 0.5,which proves the system’s confidentiality performance.We provide a feasible solution for photonic layer security,contributing to the enhancement of data transmission security and covertness.Methods The proposed ASE-based key concealment and distribution encryption optical communication system is illustrated in Fig.1.The ASE light from two ASE light sources with different central frequencies is injected into a polarization modulator(PolM)and a Mach‒Zehnder modulator(MZM),respectively.The key signal and data signal generated by an arbitrary waveform generator are loaded onto the PolM and MZM,respectively.The optical signal output from the MZM is fed into a dispersion module to broaden the signal in the time domain.Subsequently,a phase modulator(PM1)is used to perform phase encryption on the broadened optical signal.A variable optical attenuator(VOA)is employed to control the optical power output from the PolM to match that of the phase-encrypted optical signal.The phaseencrypted optical signal and the PolM-modulated optical signal are then combined into a single signal using a wavelength division multiplexer(WDM)and transmitted over single-mode fiber(SMF)to the authorized user.At the receiver,the optical signal is first compensated for dispersion using dispersion-compensating fiber(DCF),and transmission loss is compensated by an erbium-doped fiber amplifier(EDFA).Subsequently,wavelength demultiplexing is used to separate the mixed optical signal into two signals:the phase-encrypted signal and the PolM-modulated signal.The PolM-modulated optical signal passes through PC3 and enters a linear polarizer(LP).By adjusting PC3,the principal axis of the LP is set at 135°relative to the principal axis of the PolM.The signal is then converted into an electrical key signal by a photodetector(PD1).The recovered key signal is loaded onto PM2 to perform phase decryption of the data optical signal.After dispersion compensation,the data signal is recovered by PD2.Results and Discussions The simulation results demonstrate that the proposed ASE-based key concealment and distribution encryption optical communication system can effectively hide the transmitted information in both the frequency domain[Figs.2(a)and(b)]and the time domain[Fig.2(c)].At the receiver,only legitimate authorized users can fully recover the key and data information[Figs.3(b)and(d)].Figure 5 illustrates that the phase modulation index should be set within the range of 0.38 to 0.63.Within this range,a balance between encryption and decryption performance can be achieved.Under the condition of a received optical power of-10 dBm,the measured BER of the data signal is 2×10^(-7)(Fig.6).The proposed encryption system supports a maximum transmission distance of 90 km(Fig.7).To avoid affecting signal demodulation performance,the mismatch between theβ_(PM)encryption dispersion and transmission dispersion must be controlled within a specific range(Fig.8).Conclusions To address the information security challenges in metropolitan area network(MAN)optical fiber communications for the military,government,and financial sectors,we propose an encrypted optical communication system based on ASE light sources for key concealment and distribution.Leveraging the broad bandwidth and high noise characteristics of ASE light sources,the system hides both the key and data in the frequency and time domains,achieving high levels of signal transmission concealment and confidentiality.Each transmission is accompanied by the generation and updating of a unique one-time key,effectively preventing the risk of long-term key compromise.Simulation results demonstrate that the system can stably transmit OOK signals at a rate of 5 Gbit/s over a distance of 50 km with a BER of 2×10^(-7),ensuring error-free information reception.In conclusion,we not only validate the feasibility of the proposed system but also provide a viable solution for enhancing the physical layer security of optical fiber communications.
作者
杨海龙
卢冰
侯维刚
刘雪玲
张治豪
郭鹏星
郭磊
Yang Hailong;Lu Bing;Hou Weigang;Liu Xueling;Zhang Zhihao;Guo Pengxing;Guo Lei(School of Communications and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China;Institute of Intelligent Communications and Network Security,Chongqing University of Posts and Telecommunications,Chongqing 400065,China)
出处
《光学学报》
北大核心
2025年第10期12-21,共10页
Acta Optica Sinica
基金
国家自然科学基金区域联合基金(U22A2018)
国家自然科学基金(62001072,62222103)
重庆市教委创新研究群体项目(CXQT21019)。
关键词
光加密通信
放大自发辐射光
密钥隐藏与分发
信息隐蔽传输
encryption optical communication
amplified spontaneous emission light
key concealment and distribution
covert transmission of information
