@misc{cryptoeprint:2013:716,
author = {Xiao Feng and Zheng Yuan},
title = {A Secure Obfuscator for Encrypted Blind Signature Functionality},
howpublished = {Cryptology ePrint Archive, Report 2013/716},
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.