\url{https://www.heinlein-support.de/blog/security/perfect-forward-secrecy-pfs-fur-postfix-und-dovecot/#more-1085}
+\url{https://www.imperialviolet.org/2010/12/04/ecc.html}
+\url{http://arstechnica.com/security/2013/10/a-relatively-easy-to-understand-primer-on-elliptic-curve-cryptography}
+
+\url{https://github.com/ioerror/duraconf}
+
+\url{https://www.isecpartners.com/media/106031/ssl_attacks_survey.pdf}