The difference between Two-Factor Authentication and Two-Step Verification

Present day, one of the essential measures is the two-step authentication. Mainly, web pages refer to two different types of authentication: Two-Factor Authentication and Two-Step Verification. Although it is usual to think that both are the same and differ only in name, actually technically it is not.

According to Paul Moore (Information Security Consultant), differences between them are the following.

Two-Factor Authentication (2FA)

This type of authentication is based, as its name suggests, a system of "dual key", ie, which need two or more elements to log on, for example, “something we know”, “something we have” or” something we are”.

For example, a kind of Two-Factor Authentication would be to use a key generator and a fingerprint, a fingerprint and a random key, a fingerprint and a USB key or even might be with two passwords but that, after all, you need to use two or more elements to log on to a platform.

Two-Step Verification (2SV)

The Two-Step Verification is specially designed to log on by two things we know. For example, this could apply to a normal login (username + password) and an intermediate layer that prompts the user receives a random key, for example, on his phone.

While the random key or coordinate cards could be considered as "something we have" actually is "something we know" and, moreover, comes through vulnerable environments, so the attackers could get hold of it, for example, by social engineering.

In this way, we will be using two steps to logon, but one factor, that is, we will be using "two things we know."

So, why aren’t they the same?

Although they seem to be the same concept, two-factor authentication requires two different elements to log on, for example, what we know (password) and what we have (a key generator, a USB key, a smartcard, etc.) to achieve the logon. Instead, the login in two steps does not depend on these elements to access the platform, but the key can be reached via several routes of vulnerable access, such as our mail or SMS, to be actually something that we memorize and enter on the web, making it, as we said, in "something we know."

Therefore, the Two-Factor Authentication is usually more secure, as it makes the work of attackers harder, needing to steal a physical or biometric device to get the keys.