Research On Distributed Authentication Protocol For LEO Satellite Network

LEO satellite network systems represented by the Iridium system and the global star system are within the most popular research areas in recent academics.Compared with the traditional satellite network,LEO has a shorter transmission delay and lower path loss ratio,due to its low orbital height.LEO network is also superior with the advantages of terminal miniaturization and strong resistance to damage.A LEO constellation of multiple satellites can achieve true global coverage with more effective reuse of the frequencies.Growing attentions from academia and industry have been attracted onto LEO satellite network as the hottest spot of new mobile communication systems.In LEO satellite network,access authentication is a critical component to ensure network security.Under the premise of keeping security,how to design a fast and efficient authentication protocol based on the characteristics and capabilities of LEO networks is the core of current researches related to satellite network security.With consideration of LEO network limitations,and with referring to the related others' work,this thesis proposes a distributed authentication protocol and conducts a series of simulations on LEO satellite network.The major work and achievements are as follows:(1)A distributed authentication algorithm based on identity-based encryption is designed.All of users and satellites in the system register their identity in key generation center,so that the authentication between users and satellites or among satellites no longer relies on a traditional certificate mechanism with Public Key Infrastructure,which avoids the overhead brought by certificate management.The two parties involved can implement mutual authentication quickly and effectively,and by this way,authentication and access control for LEO satellite network service can be implemented,which represents a dynamic,efficient and distributed authentication protocol without relying on network control center.(2)A regional cooperative authentication protocol for LEO satellite network based on consensus mechanism is proposed.The algorithm is based on the above distributed authentication protocol and divides the dynamic topology of LEO satellite network into timeslice-oriented static regions according to distribution of access authentication and with distributed hash table as cooperative consensus.Through different schemes of storing tokens required by authentication within a region or among different regions,the proposed protocol meets the needs of performing fast handover authentication based on the consensus from regional cooperation under the premise of ensuring security.(3)Simulations are conducted based on the OPNET network simulator with STK as the software for designing LEO constellation.In the simulated LEO network scenario,with customizable traffic flows,realistic overhead of processing time and designed authentication procedures,the two proposed distributed authentication protocols are simulated and verified thoroughly.Simulation results show that response time and the performance of handover have been significantly improved with negligible increase in storage overhead,compared with traditional certificate-based mechanisms and other existing authentication protocols for satellite networks.