Research On Data Encryption/Decryption Strategy Of CCSDS Space Communication System

With the development of space communication technology, more and more users begin to send and receive information through the space wireless communication system. Relative to the ground network, the scope of space communication systems is more extensive, the diversification of topology is more frequent, the environment of system is more open, the assailment of outward is easier. Besides,the computation resource and power of space communication system is restricted,the bandwidth is narrow,the roomage and disposal power of buffer is limied,so the traditional ground network security protocol and encryption algorithm do not adapt to the space communication system. In order to ensure the data transmit safe and efficiently through the space channel, it is necessary to do deeper research about encryption/decryption strategy which is used in space communication system.This paper did deeper research about encryption and decryption strategy of the transmiting data on CCSDS space communication system,and designed a mixed encryption strategy based on SCPS-SP by deeply analysising SCPS-SP made by CCSDS and the typical encryption algorithm of cryptography. This strategy can provide better protection with much less additional communication overhead for the data units transmiting in the space link.This paper analyzed the advantages and disadvantages of DES symmetric encryption and RSA asymmetric encryption, proposed the project that making the two types of algorithm mixed to use in space communication,and verified the feasibility in theory by testing the encrypting results and cost time to analyze the safety and operational efficiency; established the space communicating data transfer model based on SCPS-SP, and made the mixed encryption algorithm and SCPS-SP together,carried out a detailed design for the implementation of encryption strategy,which including the establishment of security association(SA),RSA key exchange and the SCPS-SP encryption processing of space data units.This strategy can achieve the protection of confidentiality,integrity and authentication in three areas for the data units transmiting in space link;implemented this strategy,and validate the protective function for space data by simulating the illegal interception,tamper and forgery attack;tested the transmission efficiency of space channel, validate the advantages after implementing the encryption strategy in space communication system by comparing the impact for system performance which used mixed encryption algorithm both in IPsec and SCPS-SP.