Avoiding Two Factor Authentication Mistakes and Malware.

Two-factor authentication (2FA) is an essential security measure, but implementing it correctly can be challenging. Authenticator apps generate a time-dependent six-digit number using a secret key, but the safety of the TOTP keys relies on the authentication server not getting hacked. Most cellphone-based authenticator apps phone home, and some even send personally identifiable data about users back to the provider. Open-source apps like RedHat's FreeOTP and Aegis Authenticator are recommended for those concerned about privacy.