Cryptology ePrint Archive: BibTeX Citation of Report 2003/025

@misc{cryptoeprint:2003:025,
    author = {D.Grigoriev. I.Ponomarenko },
    title = {Homomorphic public-key cryptosystems and encrypting boolean circuits},
    howpublished = {Cryptology ePrint Archive, Report 2003/025},
    year = {2003},
    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.