A Note on Two-Factor Authentication

If you or your training participants are individuals at high-risk of being targeted by an adversary with resources, who wants to access accounts and their information, using two-factor authentication for services that offer it is highly recommended. Google, for instance, has stated that the use of two-factor authentication has drastically reduced the number of compromised accounts.

Further services, aside from Gmail and other Google tools, offering two-factor authentication include Facebook, Dropbox, and Twitter. This website (https://2fa.directory/) is an excellent tool for looking up accounts and services that currently support two-factor authentication.
It is important to use extreme caution, when using two-factor authentication systems that rely on text messages.

Recent research has indicated some popular sites, such as Facebook, being compromised by intercepting the verification codes contained within such text messages (which are not sent in any kind of encrypted format). Additionally, if you travel often and change your phone number when you do, it is important to note you can be locked out of your computer if you are not using an app like Google Authenticator.