Cryptology ePrint Archive: BibTeX Citation of Report 2011/616

@misc{cryptoeprint:2011:616,
    author = {Jiazhe Chen and Meiqin Wang and Bart Preneel},
    title = {Impossible Differential Cryptanalysis of the Lightweight Block Ciphers TEA, XTEA and HIGHT},
    howpublished = {Cryptology ePrint Archive, Report 2011/616},
    year = {2011},
    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.