@misc{cryptoeprint:2013:673,
author = {Qi Cheng and Daqing Wan and Jincheng Zhuang},
title = {Traps to the BGJT-Algorithm for Discrete Logarithms},
howpublished = {Cryptology ePrint Archive, Report 2013/673},
year = {2013},
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.