@misc{cryptoeprint:2013:580,
author = {Jalaj Upadhyay},
title = {Random Projections, Graph Sparsification, and Differential Privacy},
howpublished = {Cryptology ePrint Archive, Report 2013/580},
year = {2013},
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.