@misc{cryptoeprint:2013:638,
author = {Somindu C. Ramanna},
title = {DFA-Based Functional Encryption: Adaptive Security from Dual System Encryption},
howpublished = {Cryptology ePrint Archive, Report 2013/638},
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.