@misc{cryptoeprint:2006:101,
author = {B. Skoric and S. Maubach and T. Kevenaar and P. Tuyls},
title = {Information-theoretic analysis of coating PUFs},
howpublished = {Cryptology ePrint Archive, Report 2006/101},
year = {2006},
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.