Cryptology ePrint Archive: BibTeX Citation of Report 2007/446

@misc{cryptoeprint:2007:446,
    author = {Carlos AGUILAR MELCHOR and Philippe GABORIT},
    title = {A Lattice-Based Computationally-Efficient Private Information Retrieval Protocol},
    howpublished = {Cryptology ePrint Archive, Report 2007/446},
    year = {2007},
    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.