https://www.wilderssecurity.com/account/two-step Apparently, 2-factor authentication (or in this case 2-step verification) is available for Wilders Security Forums! Along with HTTPS encryption, this is becoming one of the most advanced forums on the Internet not just due to the users!
The "two-step verification" system was introduced in the XenForo v1.5.0 release. The overview is fairly complex at the XenForo community forum: https://xenforo.com/community/threads/two-step-verification-and-security-improvements.99881/ It's probably a bit overkill for most normal member accounts. But, anyone who wants to try it out, are certainly welcome to.