  As more sensitive data is shared and stored by third-party sites on the
internet, there will be a need to encrypt data stored at these sites. One
drawback of encrypting data is that it can be selectively shared only at a
coarse-grained level. Attribute based encryption is a public-key-based
one-to-many encryption that allows users to encrypt and decry pt data based on
user attributes. A promising application of ABE is flexible access control of
encrypted data stored in the cloud using access policies and ascribed
attributes associated with private keys and cipher text. One.One of the main
efficiency drawbacks of the existing ABE schemes is that decryption involves
expensive pairing operations and the number of such operations grows with the
complexity of the access policy. Finally, we show an implementation scheme and
result of performance measurements, which indicates a significant reduction on
computing resources imposed on users.
