Two-Factor Authentication: The Basics

Why is 2FA an Essential Part of Web Security

Two-factor authentication means that whatever application or service you’re logging in to is double-checking that the request is really coming from you by confirming the login with you through a separate venue.

You’ve probably used 2FA before, even if you weren’t aware of it. If a website has ever sent a numeric code to your phone for you to enter to gain access, for instance, you’ve completed a multi-factor transaction.

2FA is essential to web security because it immediately neutralizes the risks associated with compromised passwords. If a password is hacked, guessed, or even phished, that’s no longer enough to give an intruder access: without approval at the second factor, a password alone is useless.

2FA also does something that’s key to maintaining a strong security posture: it actively involves users in the process of remaining secure, and creates an environment where users are knowledgeable participants in their own digital safety. When a 2FA notification comes to a user, they have to answer the question, “Did I initiate that, or is someone attempting to access my account?” This underlines the importance of security with each transaction. While most other web security methods are passive, and don’t involve end users as collaborators, 2FA creates a partnership between users and administrators.

How Does 2FA Work

Different 2FA methods use varying processes, but they all rely on the same underlying workflow.

Typically, a 2FA transaction happens like this:

  1. The user logs in to the website or service with their username and password.
  2. The password is validated by an authentication server, and if correct, the user becomes eligible for the second factor.
  3. The authentication server sends a unique code to the user’s second-factor device.
  4. The user confirms their identity by approving the additional authentication from their second-factor device.

While the basic processes behind multi-factor authentication are generally the same across providers, there are many different ways to implement it, and not all methods are created equal. Let’s dive into the various types of 2FA.

Why Use 2FA

In the post-password world, strong web security relies on a dynamic approach built from a variety of tools and policies. It’s important to never rely on any single method for comprehensive protection. That means two things: (1) if you’re currently relying on passwords alone, it’s time to evolve, and using 2FA is a solid first step; and (2) 2FA is an essential security tool, but it becomes even more effective when it’s used as part of a coordinated strategy of security applications and policies.