public class: DHAgreement
a Diffie-Hellman key exchange engine.
note: This uses MTI/A0 key agreement in order to make the key agreement
secure against passive attacks. If you're doing Diffie-Hellman and both
parties have long term public keys you should look at using this. For
further information have a look at RFC 2631.
It's possible to extend this to more than two parties as well, for the moment
that is left as an exercise for the reader.