Research On The Integration Of Optical Fiber Physical Layer Key Distribution And Encryption Technology

With the rapid growth of Internet services,fiber optic networks are demanding higher and higher data transmission rates and communication capacity.At the same time,a large amount of private information is passed over fiber optic networks.Private information includes:personal account information,financial transaction records and other forms of confidential information.However,information transmitted over fiber optics can be illegally accessed or even tampered with.There are still serious threats to the security of high-speed interconnections of critical information infrastructures.For example,signal insertion attacks,such as high-power jamming attacks,signal splitting attacks,physical infrastructure attacks,etc.Security protection techniques for commercial applications use encryption algorithms based on mathematical complexity.The negotiation and updating of keys is achieved through dedicated optical transport networks.However,with the development of quantum computers with powerful decryption capabilities,there is still a threat of illegal access to the content of optical communication data encrypted based on traditional mathematical computational difficulty.For this reason,researchers have explored advanced physical security schemes for optical fiber networks from two classifications targeting from physical layer key distribution and physical layer encryption.In this paper,we propose an integrated secure communication scheme that integrates asymmetric Y-00 protocol-based physical layer key distribution technology and quantum noise stream cipher technology based on optimized optical fiber physical layer key distribution and physical layer encryption technologies for the separation of physical layer encryption and key distribution in optical communication as of right now.Simulated and experimentally confirmed in detail are the physical layer key distribution,physical layer encryption,and integrated physical layer key distribution and encryption technique and performance analysis is performed.The following is a summary of the main work and creative achievements of this paper:(1)Based on the improved Y-00 protocol,low-cost and highly compatible key distribution is realized by digital signal processing techniques.Firstly,a survival cycle-based optical fiber physical layer key distribution scheme is proposed,and the scheme does not need to change the equipment of communication nodes.The key distribution principle and implementation process are described,and the BER of the key is 1.3%using MATLAB simulation.Based on the Wiener eavesdropping model,the security of the proposed scheme is analyzed.Based on this,the key implementation process is summarized including:feature extraction,key quantization,key post-processing(information negotiation,privacy amplification),etc.Further,a long-range key distribution scheme for fiber optic links based on one-way loopback asymmetric-based Y-00 protocol is proposed.The proposed secure key distribution scheme is based on the feature extraction of the BER between the transmitted and received data of the legitimate party.It is confirmed that the key distribution rate can reach 277Kbit/s with no key BER using the 10G baud 300km offline experimental platform.Then,the randomness of the obtained keys is evaluated using the NIST test set.Similarly,the security of the proposed scheme is evaluated based on the Wiener eavesdropping model.(2)To address the challenges of long span physical layer security encryption,this paper introduces DFTS-OFDM technique for coherent optical communication systems,Raman amplifiers and ultra-low loss fibers to achieve 300 km of error-free 4QAM transmission based on quantum noise stream cipher technique without amplifier.detailed description of the DSP processing flow at the transmitter and receiver sides of the system is presented.The transmission performance and security performance under 4QAM modulation format are experimentally verified.Further,an optimized fuzzy C-mean clustering algorithm is introduced at the receiver side,and the subtractive clustering result is used as the initialized centroid of fuzzy C clustering to achieve stable clustering.The improved false bit rate performance,the computational time spent and the security performance analysis based on Wiener eavesdropping model are experimentally verified for 16 QAM/QNSC over 300 km fiber for coherent transmission without relay.(3)A novel physical layer secure optical communication system that integrates adaptive physical layer key distribution and encryption in single wavelength optical coherent communication is proposed and experimentally demonstrated for the current situation where physical layer key distribution and encryption are deployed separately.For adaptive key distribution,an adaptive key distribution scheme based on the BER difference of QAM signals mapped by asymmetric ground state Y-00 protocol is proposed.Privacy amplification using secure hash algorithm SHA3-512 is performed to obtain the real security key and calculate the mutual information quantity.A consistent secure key distribution rate of 39.3 Kbits/s is achieved in a 300km ultralow-loss fiber.An integrated key distribution and encryption approach for the physical layer is put forth,and the data signal mapping rules and signal processing flow are elaborated.The integration of the proposed key distribution scheme and the quantum noise stream cipher scheme in the same system at a single wavelength is experimentally verified.The Q-factor losses of the integrated system are 3.7 dB(optical back-to-back)and 4.8 dB(300 km),respectively,compared with the quantum noise stream cipher system.The proposed physical layer secure optical communication system solves the problem that key distribution and encryption are deployed separately through separate fiber links or wavelengths.Additionally,because only digital signal processing is utilized,no additional hardware is needed for the system.