1. What is 2FA?

Two-Factor Authentication (2FA) is a security mechanism that requires two independent forms of verification before granting access to a system, application, or device.

It strengthens authentication by combining two of the following factors:

1. Something you know → Password, PIN, security question.
2. Something you have → Phone, smart card, hardware token, authenticator app.
3. Something you are → Fingerprint, face scan, iris recognition (biometrics).

Example:

• Enter password (something you know).
• Enter a time-based one-time password (TOTP) from your phone (something you have).

2. How Does 2FA Work?

The process typically looks like this:

1. User Login → Enter username & password (first factor).
2. Generate Code → The system requests a one-time code.
3. Verification → Code is delivered via SMS, email, authenticator app, or hardware token (second factor).
4. Access Granted → Only if both factors are correct.

3. Types of 2FA Methods

🔹 Knowledge-based (Something you know)

• Passwords, PINs, secret questions.

  ⚠️ Weakest factor (can be guessed, stolen, or leaked).