Cryptology ePrint Archive: BibTeX Citation of Report 2015/686

@misc{cryptoeprint:2015:686,
    author = {Azeem Irshad and Muhammad Sher and Shahzad Ashraf and Shahzad faisal and Mahmood Ul Hassan},
    title = {Cryptanalysis for Secure and Efficient Smart-Card-Based Remote User Authentication Scheme for Multi-server Environment},
    howpublished = {Cryptology ePrint Archive, Report 2015/686},
    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.