@misc{cryptoeprint:2015:538,
author = {Sarita Agrawal and Jay Patel and Manik Lal Das},
title = {Pairing Based Mutual Healing in Wireless Sensor Networks},
howpublished = {Cryptology ePrint Archive, Report 2015/538},
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.