Cryptology ePrint Archive: BibTeX Citation of Report 2014/644

@misc{cryptoeprint:2014:644,
    author = {Ravikumar Selvam and Dillibabu Shanmugam and Suganya Annadurai},
    title = {Side Channel Attacks: Vulnerability Analysis of PRINCE and RECTANGLE using DPA},
    howpublished = {Cryptology ePrint Archive, Report 2014/644},
    year = {2014},
    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.