Cryptology ePrint Archive: BibTeX Citation of Report 2012/437

@misc{cryptoeprint:2012:437,
    author = {Amit Sahai and Hakan Seyalioglu and Brent Waters},
    title = {Dynamic Credentials and Ciphertext Delegation for Attribute-Based Encryption},
    howpublished = {Cryptology ePrint Archive, Report 2012/437},
    year = {2012},
    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.