@misc{cryptoeprint:2013:563,
author = {Zvika Brakerski and Guy N. Rothblum},
title = {Virtual Black-Box Obfuscation for All Circuits via Generic Graded Encoding},
howpublished = {Cryptology ePrint Archive, Report 2013/563},
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.