Cryptology ePrint Archive: BibTeX Citation of Report 2015/615

@misc{cryptoeprint:2015:615,
    author = {Nasour Bagheri, Masoumeh Safkhani and Hoda Jannati},
    title = {Security Analysis of Niu et al. Authentication and Ownership Management Protocol},
    howpublished = {Cryptology ePrint Archive, Report 2015/615},
    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.