Hansen, R. J. (2018a, May 14). Don’t Panic. Retrieved from https://lists.gnupg.org/pipermail/gnupg-users/2018-May/060317.html

Hansen, R. J. (2018b, May 14). Efail press release. Retrieved from https://lists.gnupg.org/pipermail/gnupg-users/2018-May/060334.html

Koch, W. (2018, May 14). Efail or OpenPGP is safer than S/MIME. Retrieved from https://lists.gnupg.org/pipermail/gnupg-users/2018-May/060315.html

Mirimir. (2018, May 14). Attention PGP Users: New Vulnerabilities Require You to Take Action Now. Retrieved from https://lists.gnupg.org/pipermail/gnupg-users/2018-May/060316.html