Cryptology ePrint Archive: BibTeX Citation of Report 2015/293

@misc{cryptoeprint:2015:293,
    author = {Pratish Datta and Ratna Dutta and Sourav Mukhopadhyay},
    title = {Fully Secure Unbounded Revocable Attribute-Based Encryption in Prime Order Bilinear Groups via Subset Difference Method},
    howpublished = {Cryptology ePrint Archive, Report 2015/293},
    year = {2015},
    note = {\url{http://eprint.iacr.org/}},
}

You will need the url.sty package (comes with most LaTeX installations) for the last line. Otherwise, remove the \url command.