What’s the Difference Between 2FA and 2SV?

Last updated on February 18, 2025

The more popular an idea, the more misconceptions around it. Two-Factor Authentication (2FA) is no different. We already discussed what’s the difference between MFA and 2FA, and explained that even though these two terms are sometimes used interchangeably, they may be two different things. But MFA and 2FA are not the only two commonly confused concepts.

In this article, we describe what’s the difference between Two-Step Verification (2SV) and Two-Factor Authentication (2FA).

Semantics and Factors

Some experts use the name Two-Step Authentication (2SA) instead of Two-Step Verification (2SV).

If we assume verification and authentication are synonyms, then the only real semantic difference between Two-Step Authentication and Two-Factor Authentication lies in two words: “step” and “factor”.

Both a step of authentication and a factor of authentication are pieces of evidence that a user has to present during authentication to prove they are who they say they are.

There are three authentication factors:

• Knowledge Factor – what the user knows, e.g., a password
• Possession Factor – what the user has, e.g., a mobile phone, a security key
• Inherence Factor – who the user is, biometrics, e.g., a fingerprint

Two-Factor Authentication vs. Two-Step Verification

Two-Step Verification (2SV) is a type of authentication that uses two factors of authentication.

Two-Factor Authentication (2FA) is a type of authentication that uses two distinct factors of authentication.

Emphasis on two distinct factors.

Any two steps are sufficient to say an authentication is a Two-Step Authentication.

However, to call an authentication a Two-Factor Authentication, two distinct factors must be used.

These two sentences hold true:

• A process of authentication that uses the Knowledge Factor twice is 2SV but not 2FA.
• A process of authentication that uses the Knowledge Factor and the Possession Factor is both 2SV and 2FA.

Similarly, if you must use a password, a PIN, and your smartphone to log in to your application, then you are undergoing Three-Step Authentication. But this is only Two-Factor Authentication because you only used the Knowledge Factor (twice) and the Possession Factor.

Example of Two-Step Authentication

If you ask your user to provide two different passwords, one after another, then it is Two-Step Verification because the user has to go through two steps. However, this example is not Two-Factor Authentication because this authentication uses something you know twice. The same goes for even the most secure authentication methods: a passwordless login that requires two separate WebAuthn security keys is 2SV but not 2FA.

One example of Two-Step Authentication that is not Two-Factor Authentication is the combination of a password and the Email Link authentication method.

The Email Link authentication method is an example of something you know because the password to your email account is all you need to complete authentication. In the end, you need to provide a password twice, which is Two-Step Authentication but not Two-Factor Authentication.

Note that the Email Link authentication method is not the Possession Factor. You can access your email account both from your computer and your mobile device, so at no point is the system checking your possession of a device. The system is only checking your access to your email account, which is canonically only protected with a password. Naturally, we recommend you enable 2FA on your email account, too.

Example of Two-Factor Authentication

Rublon’s Mobile Push is an example of the Possession Factor.

Note that the preceding diagram shows Two-Factor Authentication. First, you provide your password – something you know. Then, you receive a push notification on your mobile phone. Your mobile device is something you have because you need to prove the possession of the mobile device to complete authentication.

Since the preceding authentication consists of two steps, it is also Two-Step Verification.

2FA is sufficient in most cases. Still, you can further improve the security of the preceding authentication by introducing the third factor. To add the Inherence Factor to your Rublon Authenticator mobile app, enable Fingerprinting or Face ID.

Two-Step Verification May Not Be Enough

Many products advertise Two-Step Verification. They may mean Two-Factor Authentication since every Two-Factor Authentication is also Two-Step Authentication. Still, if a security provider only offers Two-Step Verification, then it should not come as a surprise that some customers are concerned about their security.

A big part of why 2FA is so secure is that it uses two distinct authentication factors to prove a user’s identity. If you use two factors of the same type, you are still much more secure than if you only used a password, but never as secure as with 2FA.

What significantly improves security is adding more different authentication factors to the authentication process, not adding five same factors.

Furthermore, if you work in a specific industry like Healthcare, Financial, or Retail, you must comply with security regulations such as NYDFS, NAIC, PCI DSS, or HIPAA. These regulations require you to deploy Two-Factor Authentication in your workforce. Two-Step Verification may be insufficient to meet the conditions of these requirements.

Security In Discussions About Steps and Factors

When discussing security theory, we need to forget about the practical security of each authentication method. What that means is that two distinct authentication factors are enough to say a given authentication process is 2FA. It may not be the most secure process. There might be ways to go around it or break it, but these concerns, though important, are beside the scope of simply deciding whether the identity verification process is 2FA or 2SV.

Get 2FA

If you use Two-Step Verification (2SV), ensure it is also Two-Factor Authentication (2FA). If your 2SV is not 2FA, then we recommend you get 2FA instead.

Rublon offers Two-Factor Authentication (2FA) that conforms with a wide range of regulations, from NIST to HIPAA. Our Rublon Authenticator mobile app ensures comfortable one-tap authentication using the Mobile Push authentication method. We also support WebAuthn/U2F Security Key and offer the possibility of enabling a fingerprint lock on Rublon Authenticator.

Two-Factor Authentication is what we do. If you want to deploy 2FA in your workforce, we will be happy to help.

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