Cryptology ePrint Archive: BibTeX Citation of Report 2015/257

@misc{cryptoeprint:2015:257,
    author = {Vadim Lyubashevsky and Thomas Prest},
    title = {Quadratic Time, Linear Space Algorithms for Gram-Schmidt Orthogonalization and Gaussian Sampling in Structured Lattices},
    howpublished = {Cryptology ePrint Archive, Report 2015/257},
    year = {2015},
    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.