Cryptology ePrint Archive: BibTeX Citation of Report 2003/127

@misc{cryptoeprint:2003:127,
    author = {B. Ya. Ryabko and V.A. Monarev},
    title = {Using Information Theory Approach to  Randomness Testing},
    howpublished = {Cryptology ePrint Archive, Report 2003/127},
    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.