Cryptology ePrint Archive: BibTeX Citation of Report 2015/944

@misc{cryptoeprint:2015:944,
    author = {Palash Sarkar and Shashank Singh},
    title = {New Complexity Trade-Offs for the (Multiple) Number Field Sieve Algorithm in Non-Prime Fields},
    howpublished = {Cryptology ePrint Archive, Report 2015/944},
    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.