Cryptology ePrint Archive: BibTeX Citation of Report 2008/148

@misc{cryptoeprint:2008:148,
    author = {Roberto M. Avanzi and Clemens Heuberger and Helmut Prodinger},
    title = {Redundant $\tau$-adic Expansions I: Non-Adjacent Digit Sets and their Applications to Scalar Multiplication},
    howpublished = {Cryptology ePrint Archive, Report 2008/148},
    year = {2008},
    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.