@misc{cryptoeprint:2005:259,
author = {Bo Gyeong Kang and Moon Sung Lee and Je Hong Park},
title = {Efficient Delegation of Pairing Computation},
howpublished = {Cryptology ePrint Archive, Report 2005/259},
year = {2005},
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.