@misc{cryptoeprint:2015:357,
author = {Ming Li, Yupeng Jiang and Dongdai Lin},
title = {A Group-theory Method to The Cycle Structures of Feedback Shift Registers},
howpublished = {Cryptology ePrint Archive, Report 2015/357},
year = {2015},
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.