Multi-factor authentication (MFA): Definition, examples, and benefits

What is multi-factor authentication (MFA)? 

Multi-factor authentication (MFA) is a security process that requires users to verify their identity through more than one form of authentication before gaining access to a resource. Instead of relying solely on a password, MFA combines multiple authentication factors for identity authentication:

• Something you know, such as your password, PIN, or the answer to a security question like your first pet’s name.
• Something you have, such as your smartphone (for receiving text codes), a physical security key, or an app that generates temporary codes.
• Something you are, such as your fingerprints, facial recognition, or voice patterns, which are all considered forms of personally identifiable information (PII).

This layered approach makes unauthorized access much harder. Even if criminals steal your password, they still need your second authentication factor to enter the account.

Benefits of multi-factor authentication

Using MFA adds an extra layer of protection beyond a simple password. Since it significantly improves security, MFA makes it more difficult for attackers to access your accounts.

With MFA, you get:

• A reduced risk of data breaches. Since stolen passwords cause many security breaches, MFA blocks this attack method.
• Protection of sensitive information. MFA ensures that personal information and other critical assets remain protected even if your login details are exposed.
• Compliance with security standards. Many online services now require or strongly recommend MFA as a baseline security practice for protecting personal accounts.
• Prevention of identity theft and account misuse. The extra security step makes it much harder for criminals to impersonate you or access your accounts.

How does multi-factor authentication work?

Multi-factor authentication confirms your identity using multiple verification methods before allowing account access. Each factor comes from a different category (like something you know, have, or are), making it much harder for attackers to compromise all at once.

The authentication process typically follows these steps:

1. Login attempt. You start by entering your username and password, which act as the first layer of authentication.
2. System request for additional verification. The system prompts you to provide another form of proof, such as a one-time code from an authentication app, a fingerprint scan, or a hardware security key.
3. Verification. The system verifies your second factor by comparing it to stored data (such as your saved fingerprint or a generated authentication code).
4. Access granted. If all factors match, you gain access. If not, the system blocks the attempt and often sends a security alert.

The three main types of multi-factor authentication  

Authentication factors fall into three main categories, along with several emerging methods.

Something you know (knowledge factor)

This category includes information that only you should know, such as:

• Passwords or PINs.
• Security questions.
• Passphrases.

While widely used, knowledge factors are also the most vulnerable because they can be guessed, phished, or stolen in a data breach. Because of this vulnerability, MFA combines passwords with other security methods that are harder to compromise.

Something you have (possession factor)

This factor involves a physical item you possess, such as:

• Smartphone authentication apps. 
• Hardware tokens or smart cards.
• USB or NFC security keys.

Even with stolen passwords, attackers would need physical access to your device, making breaches much harder.

Something you are (inherence factor)

This factor relies on biometric identifiers or unique physical traits. Examples of biometric authentication include:

• Fingerprint scans.
• Facial or iris recognition.
• Voice patterns.

Biometric authentication is highly secure because physical traits are nearly impossible to replicate. 

Other types of MFA

Beyond the traditional three factors, modern systems now include new types of MFA.

• Location-based MFA: Grants or denies access depending on the user’s geographical location or IP address.
• Adaptive MFA (risk-based MFA): Uses artificial intelligence to analyze login patterns in real time and automatically adjust security requirements based on perceived risk.
• Passwordless MFA: Eliminates passwords entirely, relying on biometrics or hardware keys for faster and more secure authentication methods.

Multi-factor authentication examples

Examples of knowledge factors

• A user enters their account password and then types a one-time code generated by a hardware token.
• A company portal prompts employees to answer a personal question after entering their password.

While easy to implement, passwords alone remain vulnerable to phishing and data breaches. For increased safety, consider having different security answers and PINs per device. 

Examples of possession factors

• A mobile phone or tablet receives an SMS or push notifications to approve a login for a secure application.
• A USB security key or smart card that you need to use to access a system.
• A hardware token generates a time-sensitive code used during login for added verification.

Examples of inherence factors

• A fingerprint scan to unlock a device, access a banking app, or make a transaction online.
• Facial recognition or voice-pattern scanning used during sign-in.

Modern systems may also use behavioral biometrics like typing speed or mouse movement. These methods are usually seamless for users while raising the bar for attackers.

What is the difference between multi-factor authentication (MFA) and two-factor authentication (2FA)?

Two-factor authentication (2FA), also known as two-step verification, requires two different types of credentials when logging in. For example, the system could ask you for a password (something you know) and a one-time code (something you have).

A multi-factor authentication system, on the other hand, involves two or more distinct types of factors, offering greater flexibility and stronger security. A system could require a password, a hardware token, and a fingerprint scan to confirm your identity. 

In simple terms, 2FA is a subset of MFA. All 2FA counts as MFA, but MFA isn’t limited to just two factors. Both, however, are stronger forms of security than having just a password to secure your data.

What’s the difference between MFA and single sign-on (SSO)?

Multi-factor authentication verifies identity with multiple credentials. In contrast, single sign-on (SSO) provides convenience by letting users access multiple apps with one login.

For example, when you sign in to your Google account and automatically gain access to Gmail, Google Drive, and YouTube without re-entering credentials, that’s SSO in action. MFA, meanwhile, would require an extra verification step (like an authentication code) before you access those services. 

MFA strengthens how securely a user logs in, while SSO simplifies how many times they need to log in. The two often work best together because SSO streamlines access while MFA ensures that every sign-in remains secure.

How do you turn on multi-factor authentication?

Turning on MFA usually involves activating a security feature in your account settings and linking an additional verification method, such as a phone number, email, or authentication app. However, the exact steps differ depending on the service or platform you’re using. 

When possible, choose authentication apps or security keys over SMS codes for better protection against SIM swapping. It’s also a good practice to review your recovery options (such as backup codes or alternative trusted devices) and store them safely offline.

Multi-factor authentication best practices

Even the most secure system can be undermined by poor MFA implementation or unsafe user habits. To make sure you get the full benefits of multi-factor authentication, follow these best practices:

• Use strong, unique authentication factors. Don’t rely on the same password or PIN across multiple accounts. Mix different types of factors, like an authenticator app and biometric verification, to boost protection.
• Enable MFA on all critical accounts. Activate MFA on every account that handles sensitive information. Prioritize email and banking logins because these are common entry points for cybercriminals. Breaches on these accounts can lead to identity theft, financial loss, or unauthorized access to other connected services.
• Regularly update your MFA methods. Replace outdated recovery numbers or email addresses so you can regain access if needed. Reset software tokens after changing devices and review permissions so only trusted devices remain active.
• Activate MFA notifications. Enable alerts for new sign-in attempts so you can quickly spot suspicious user activity and act before damage occurs.
• Avoid SMS-based MFA when possible. Codes sent via text message can be intercepted through SIM swapping attacks. Authentication apps or security keys provide better protection.
• Stay vigilant against phishing attempts. Cybercriminals often use fake MFA prompts or links to conduct phishing attacks and steal credentials. As a rule of thumb, never share your verification codes, and be familiar with the different types of phishing.

Multi-factor authentication is one of the simplest, most effective ways to strengthen your online security. However, it should be part of a broader defense strategy that covers all your devices.

For complete protection against cyber threats, NordProtect offers powerful tools like identity theft protection and seamless dark web monitoring. Together, they help safeguard your identity and data, no matter where you log in.