Cryptology ePrint Archive: BibTeX Citation of Report 2011/020

@misc{cryptoeprint:2011:020,
    author = {Antoine Joux and Vanessa Vitse},
    title = {Cover and Decomposition Index Calculus on Elliptic Curves made practical. Application to a seemingly secure curve over $\F_{p^6}$},
    howpublished = {Cryptology ePrint Archive, Report 2011/020},
    year = {2011},
    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.