Aside from “two” and “multi,” you’ll notice that these terms are exactly the same. That’s because they 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 the words “factor” and “authentication.”
Authentication is all about 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 the traditional authentication and find a way into your account.
If your accounts are secured by a password alone, you’re technically using 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 an authentication process that requires a certain number of factors. For example, five-factor authentication means that the user needs five different factors to log in. Generally, a higher number of factors lead to better security since a hacker would have to compromise every single factor to get into the account.
That leads us to the difference between two-factor authentication and multifactor authentication. In short, two-factor authentication refers to authentication through exactly two factors while multifactor authentication 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 in practice. 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 2023. Your options depend on the specific website or app you’re using.
Authenticator apps are one of the simplest and most reliable methods of two-factor authentication or multifactor authentication. Google Authenticator is a good default, but there are many other apps out there, 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’ll be able to 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 the app you’re using, 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 two-factor authentication codes. While these are still commonly used by many websites and apps, we recommend switching to an alternative option if you’re still using 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, you should 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 just like the key 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 ultimately comes down to your personal preference.
At this point, you understand the difference between two-factor and multifactor authentication. Theoretically, while every additional factor improves your security, a reliable second factor should be more than enough to protect most users.
The next step is to start using a two-factor authentication method that makes sense for you. The available options vary from one website to another. Most users are satisfied with the convenience of an authenticator app on their phones, but security keys are a great alternative that offer even more protection from certain kinds of attacks.