School of Electronic and Information Engineering Beihang University Beijing 100191 China;
School of Electronic and Information Engineering Beihang University Beijing 100191 China;
School of Electronic and Information Engineering Beihang University Beijing 100191 China;
School of Electronic and Information Engineering Beihang University Beijing 100191 China;
Department of Computer and Information of Science and Engineering University of Florida Gainesville FL 32611 USA;
space information network; network architecture; data encryption; key management; access authentication;