Cryptology ePrint Archive: BibTeX Citation of Report 2015/902

@misc{cryptoeprint:2015:902,
    author = {Kexin Qiao and Lei Hu and Siwei Sun},
    title = {Differential Security Evaluation of Simeck with Dynamic Key-guessing Techniques},
    howpublished = {Cryptology ePrint Archive, Report 2015/902},
    year = {2015},
    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.