Cryptology ePrint Archive: BibTeX Citation of Report 2005/326

@misc{cryptoeprint:2005:326,
    author = {Patrick P. Tsang, Man Ho Au, Joseph K. Liu, Willy Susilo, Duncan S. Wong},
    title = {A Suite of Non-Pairing ID-Based Threshold Ring Signature Schemes with Different Levels of Anonymity},
    howpublished = {Cryptology ePrint Archive, Report 2005/326},
    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.