School of Computer Science;
Shaanxi Normal University;
Xi'an 710119;
China;
State Key Laboratory of Information Security;
Institute of Information Engineering;
Chinese Academy of Sciences Beijing 100093;
China;
School of Computer Science and Technology;
Wuhan University of Technology;
Wuhan 430070;
China;
State Key Laboratory of Integrated Services Networks;
Xidian University;
Xi'an 710071;
China;
public-key; encryption; identity-based; hash; proof; system; lattice; updatable; leakage-resilience;