Cryptology ePrint Archive: BibTeX Citation of Report 2013/676

@misc{cryptoeprint:2013:676,
    author = {Siwei Sun, Lei Hu, Peng Wang, Kexin Qiao, Xiaoshuang Ma, Ling Song},
    title = {Automatic Security Evaluation and (Related-key) Differential Characteristic Search: Application to SIMON, PRESENT, LBlock, DES(L) and Other Bit-oriented Block Ciphers},
    howpublished = {Cryptology ePrint Archive, Report 2013/676},
    year = {2013},
    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.