Cryptology ePrint Archive: BibTeX Citation of Report 2010/480

@misc{cryptoeprint:2010:480,
    author = {Shigeo Tsujii and Masahito Gotaishi},
    title = {Enhanced STS using Check Equation --Extended Version of the Signature scheme proposed in the PQCrypt2010--},
    howpublished = {Cryptology ePrint Archive, Report 2010/480},
    year = {2010},
    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.