@misc{cryptoeprint:2007:212,
author = {Andrey Khalyavin},
title = {The constructing of $3$-resilient Boolean functions of $9$ variables with nonlinearity $240$.},
howpublished = {Cryptology ePrint Archive, Report 2007/212},
year = {2007},
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.