Two-Factor Authentication vs. Multifactor Authentication: What’s the Difference?

In 2024, most internet users are probably familiar with the terms two-factor authentication (2FA) and multifactor authentication (MFA). However, you may not know whether there’s a difference between these or if the terms refer to the same thing.

Even though some people use these terms interchangeably, they aren’t exactly the same. We’ll review the distinction between 2FA and MFA and explain why it could be relevant if you want to keep your online accounts as secure as possible.

Key takeaways:

• Generally, 2FA is authentication through exactly two factors, yet MFA could refer to any form of authentication that requires more than one factor.
• Many forms of authentication can verify login attempts and passwords, such as authenticator apps and security keys.
• Ensure you utilize a 2FA method that makes sense for your situation.

Aside from “two” and “multi,” these terms are the same. Both refer to the number of factors used to authenticate a given access attempt. To understand the difference between 2FA and MFA, you first need to understand “factor” and “authentication.”

Authentication is confirming that the right person is logging into a particular account. Passwords are the most straightforward authentication method for online accounts. As long as you’re the only person who knows your password, entering the password is enough to authenticate the login attempt.

Unfortunately, passwords are far from foolproof on their own. More than 60% of all breaches stem from compromised credentials. By guessing, stealing, or otherwise gaining usernames and passwords, hackers can perform traditional authentication and find a way into your account.

If your accounts are secured by a password alone, you technically use single-factor authentication. The password is the only factor required to complete the authentication practice. A hacker can log in simply by acquiring your password, which makes your accounts relatively vulnerable.

The phrase “X-factor authentication” refers to a process that requires a certain number of factors. For example, five-factor authentication requires five different factors to log in. Generally, more factors lead to better security since a hacker must compromise every factor to get into the account.

While 2FA refers to authentication through exactly two factors, MFA could refer to any form of authentication that requires more than one factor.

This means that 2FA is technically a subset of MFA. It doesn’t matter whether you’re working with two, three, four, five, or even 10 factors — all of these protocols can be referred to as MFA.

Most accounts are secured with one or two factors, so the difference between 2FA and MFA isn’t always relevant. However, it’s important to understand that MFA could theoretically include any number of factors beyond one, while 2FA is specifically used to refer to authentication processes that involve exactly two factors.

There are many forms of authentication used to verify login attempts alongside passwords. In this section, we’ll go over some of the most common factors in 2024. Your options depend on the specific website or app you’re using.

Authenticator apps are one of the simplest and most reliable methods of 2FA or MFA. Google Authenticator is a good default, but many other apps exist, such as Microsoft Authenticator, Authy, and Duo Mobile. Some password managers even offer built-in authenticators with similar functionality.

After installing an authenticator app on your phone, you can confirm new login attempts without receiving a short message service (SMS), email, or other message. The authentication attempt usually appears as a push notification. Depending on your app, you may have to enter a code or tap the “Approve” button.

If you haven’t used an authenticator app before, you may have experience with SMS or email-based 2FA codes. While these are still commonly used by many websites and apps, we recommend switching to an alternative option if you still use SMS or email.

One key issue with these channels is that it’s easy for hackers to imitate an email or SMS. On the other hand, it would be much more difficult to imitate a legitimate request from an authenticator app.

Furthermore, SMS is an unencrypted communication channel, which makes messages vulnerable to being intercepted. Even if SMS seems like the most convenient option, stick with an authenticator app, security key, or other reliable alternative.

Dedicated security keys are physical devices that can communicate in various ways — for example, over Bluetooth or after being plugged into a computer via USB.

Security keys are popular among cybersecurity enthusiasts. They don’t depend on an internet connection, and they preclude any plausible method that could be used to get into your accounts without the physical device.

The chance of your phone being hacked or compromised is small. Still, security keys completely remove that possibility by not connecting to the internet at all. With that in mind, you can think of them as keys like the ones you use to get into your home.

At the same time, there’s no reason to be concerned about your security if you use a conventional authenticator app. Whether to stick with authenticator apps or opt for a physical security key depends on your preference.