@misc{cryptoeprint:2013:748,
author = {Kenneth G. Paterson and Bertram Poettering and Jacob C.N. Schuldt},
title = {Plaintext Recovery Attacks Against WPA/TKIP},
howpublished = {Cryptology ePrint Archive, Report 2013/748},
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.