Cryptology ePrint Archive: BibTeX Citation of Report 2005/198

@misc{cryptoeprint:2005:198,
    author = {Ahto Buldas and Peeter Laud and Märt Saarepera and Jan Willemson},
    title = {Universally Composable Time-Stamping Schemes with Audit},
    howpublished = {Cryptology ePrint Archive, Report 2005/198},
    year = {2005},
    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.