@misc{cryptoeprint:2011:518,
author = {Ran Canetti and Ben Riva and Guy N. Rothblum},
title = {Two 1-Round Protocols for Delegation of Computation},
howpublished = {Cryptology ePrint Archive, Report 2011/518},
year = {2011},
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.