Department of Electronic and Communication Engineering;
Beijing Electronic Science and Technology Institute;
Beijing 100070;
China;
Department of Cryptography Science and Technology;
Beijing Electronic Science and Technology Institute;
Beijing 100070;
China;
School of Telecommunication Engineering;
Xidian University;
Xi'an 710071;
China;
lattice; small integer solution problem; key agreement protocol; provable security; eCK model;