Cryptology ePrint Archive: BibTeX Citation of Report 2012/621

@misc{cryptoeprint:2012:621,
    author = {Kitae Jeong and HyungChul Kang and Changhoon Lee and Jaechul Sung and Seokhie Hong},
    title = {Biclique Cryptanalysis of Lightweight Block Ciphers PRESENT, Piccolo and LED},
    howpublished = {Cryptology ePrint Archive, Report 2012/621},
    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.