Research And Implementation Of End-to-End Encryption System For Satellite

Satellite communication uses artificial earth satellites as relay stations to achieve communication between ground stations or between ground stations and spacecraft.Because of its advantages of long-distance communication,wide coverage,freedom from natural disasters and bad weather,it has become an important auxiliary communication for ground mobile communication,especially for emergency rescue communication,state secret information communication,long-distance communication,and remote area communication.Etc.have very important significance.However,due to the lack of corresponding physical layer protection in the space communication link of the satellite communication system,its open status and satellite exposure,etc.,make the information transmitted by it very easy to be intercepted by the listening station,involving state secret information Theft incidents occur from time to time,seriously threatening the privacy of users,so how to ensure the security of end-to-end satellite communications has become a widespread concern in the global communications field.This paper mainly studies the traditional end-to-end voice encryption technology,voice watermarking technology and satellite communication mechanism,and proposes an end-to-end voice encryption technology that can resist the low-speed voice coding of satellite communication,encrypting the voice signal to be transmitted so In the satellite communication system,all exist in the form of ciphertext to ensure the confidential communication of the satellite communication system.In this encryption algorithm,in-depth research on the transformation domain voice encryption algorithm,voice frame synchronization,key transmission and other issues involved in end-to-end secure communication is carried out.The main work of the paper is as follows:(1)Firstly,I found some defects in the existing end-to-end voice scrambling algorithm based on the end-to-end encryption mechanism.For example,the encryption algorithm is relatively simple that hard to meet the security requirements of communication systems.The spectrum components were analyzed by using frequency domain characteristics of the voice signal,and the frequency spectrum structure is segmented according to the different effects of its frequency band on the voice signal,which are the basics of the scrambling experiment to divide the integrated frequency bands into asymmetrical group.Then,a new encryption algorithm based on frequency-domain scrambling is obtained by performing different scrambling methods on adjacent speech frames.(2)Focus on the synchronization of voice frames and the transmission of keys in satellite communication systems.Drawing on the idea of voice watermarking,the synchronization algorithm of voice watermarking is used as the synchronization algorithm of frequency domain scrambling to solve the problem of synchronization of voice frames.Then the encryption key is embedded in the voice frame to be transmitted to realize the transferable key transmission,ensuring that the key embedded in the voice signal to the characteristics of the satellite communication channel transmission,so as to achieve the purpose of digital signal transmission in the analog channel.(3)Further,in order to verify the feasibility of the encryption algorithm implemented in the satellite communication system,a real-time call simulation experiment was carried out on the Eurostar phone.The STM32F405 RG chip with fast calculation speed,good performance stability and low cost is used as the core component to build an end-to-end voice encryption and decryption system.The software simulation and actual call test show that the encryption system can be better applied to Eurostar handheld terminals,and the whole of the end-to-end secure communication of Eurostar phones is realized,which provides a safe and efficient solution for the secure communication of Eurostar phones.