financially supported by the National Natural Science Foundation of China(No.61303216,No.61272457,No.U1401251,and No.61373172);the National High Technology Research and Development Program of China(863 Program)(No.2012AA013102);National 111 Program of China B16037 and B08038
With the rapid development of computer technology, cloud-based services have become a hot topic. They not only provide users with convenience, but also bring many security issues, such as data sharing and privacy issu...