LAUSR

Attribute based encryption is an effective method which can solve the access control problem of cloud storage. Realizing both efficient attributes revocation and outsourcing decryption would enhance mobile user experience. In this paper, we present a new scheme of Key-Policy Attribute Based Encryption in hybrid cloud system. In our scheme, the most of computation in the decryption process can be outsourced to the cloud and the efficiency of system is improved. In addition, the attributes of malicious users or expired ones can be revoked with unrelated users offline. Moreover system consumes a little resources rather than rebuilds the system or updates all data immediately. We also give a proof of security, a detailed description of execution and efficiency analysis.