@misc{cryptoeprint:2014:254,
author = {Thomas Pöppelmann and
Lëo Ducas and
Tim Güneysu},
title = {Enhanced Lattice-Based Signatures on Reconfigurable Hardware},
howpublished = {Cryptology ePrint Archive, Report 2014/254},
year = {2014},
note = {\url{https://ia.cr/2014/254}},
}
You will need the url.sty package (comes with most LaTeX installations) for the last line. Otherwise, remove the \url command.