\section{A note on Diffie Hellman Key Exchanges}
\label{section:DH}
A common question is which Diffie Hellman (DH) Parameters should be used for
Diffie Hellman key
exchanges\footnote{\url{http://crypto.stackexchange.com/questions/1963/how-large-should-a-diffie-hellman-p-be}}.
We follow the recommendations in ECRYPT II~\cite[chapter 16]{ii2011ecrypt}
Where configurable, we recommend using the Diffie Hellman groups
defined for IKE, specifically groups 14-18 (2048--8192 bit MODP~\cite{rfc3526}).
These groups have been checked by many eyes and can be assumed to be secure.
For convenience, we provide these parameters as PEM files. \todo{put
them on the server and insert URL here}.