What is Two-Factor Authentication (2FA)?

Two-factor authentication (2FA) adds an extra layer of security by requiring two different types of proof to verify your identity. Unlike using a single password, which could be guessed or stolen, 2FA combines multiple forms of authentication to ensure better protection against unauthorised access.

How Does 2FA Work?

Two-factor authentication typically involves providing two types of evidence from these three categories:

• Something you know: e.g., a password or PIN.

• Something you have: e.g., a physical card, a key, or a phone.

• Something you are: e.g., your fingerprint, voice, or facial recognition.

For example:

• Logging into an account might require your password (something you know) and a verification code sent to your phone (something you have).

• Using a credit card at an ATM requires the card itself (something you have) and your PIN (something you know).

This combination significantly reduces the risk of unauthorised access, even if one factor is compromised.

Everyday Examples of 2FA

• Photo ID verification: You present a photo ID (something you have) and must match the photo (something you are).

• ATM withdrawals: Using your debit card (something you have) alongside your PIN (something you know).

• Smartphone logins: Entering a password (something you know) and confirming your identity with a fingerprint (something you are).

Why Use Two-factor Authentication?

Cybercriminals are sneaky and constantly finding new ways to breach security. Two-factor authentication (2FA) provides a vital extra layer of defence by requiring two independent forms of verification. Even if one factor, like a password, is stolen, the second factor helps keep your account secure.

Multi-factor authentication (MFA) takes this even further by incorporating two or more factors, adding additional safeguards. Whether you’re protecting personal accounts or sensitive business data, 2FA and MFA are simple yet highly effective tools to reduce the risks of phishing attacks, password leaks, and unauthorised access.

This sketch features in my book Big Ideas Little Pictures