Cryptology ePrint Archive: BibTeX Citation of Report 1998/002

@misc{cryptoeprint:1998:002,
    author = {A. De Santis, G. Di Crescenzo, O. Goldreich, and G. Persiano.},
    title = {The Graph Clustering Problem has a Perfect Zero-Knowledge Proof},
    howpublished = {Cryptology ePrint Archive, Report 1998/002},
    year = {1998},
    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.