Cryptology ePrint Archive: BibTeX Citation of Report 2014/720

@misc{cryptoeprint:2014:720,
    author = {Dennis Hofheinz and Akshay Kamath and Venkata Koppula and Brent Waters},
    title = {Adaptively Secure Constrained Pseudorandom Functions},
    howpublished = {Cryptology ePrint Archive, Report 2014/720},
    year = {2014},
    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.