@misc{cryptoeprint:2011:403,
author = {Carolyn Whitnall and Elisabeth Oswald},
title = {A Fair Evaluation Framework for Comparing Side-Channel Distinguishers},
howpublished = {Cryptology ePrint Archive, Report 2011/403},
year = {2011},
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.