Autor: Codenga 13.06.2024

2FA - How It Works

Two-factor authentication (2FA) is a method of securing access to an account or system that requires the user to provide two different forms of authentication.

In addition to standard login, we need to provide another element that confirms we are the rightful person. This second element can be:

• Something only we know, such as a PIN code,
• Something only we possess, such as a phone,
• Something unique to us, such as a fingerprint.

2FA - Example Authentication Steps

Imagine logging into a web application.

• Step 1: You enter your username and password.
• Step 2: A code is sent to your phone via SMS, which you must enter to complete the login.

This is an example of two-factor authentication. SMS codes are often used in the second step due to their simplicity and convenience. In systems where security is critical, more complex solutions such as special hardware keys are used.

Why Use 2FA

Using two-factor authentication significantly improves the security of our user accounts. Even if someone learns your password, they still won't be able to pass the second verification step.

With 2FA, we have a much lower risk of unauthorized access to our accounts. This positively impacts the trust in the given application or service.

Services Using 2FA

Many popular services and applications use 2FA: Google, Facebook, Microsoft, Apple, and more. This authentication method is also frequently used by banks.

In some services, 2FA is an additional option that we can activate if we want enhanced login security.

Limitations and Security of 2FA

Using 2FA greatly enhances security, but like any technology, it has its limitations.

A significant problem is losing the element responsible for the second login step. For example, if we lose the phone where we receive SMS codes, logging into the service may become impossible.

For many people, the additional login step can be inconvenient to use, especially if it requires additional devices or complex procedures.

There are also certain attack methods that can intercept authentication codes. Therefore, it's important to remember that 2FA will never be 100% secure—such technologies simply don't exist.

Summary

Two-factor authentication (2FA) is a popular and proven method to increase our login security. SMS codes sent to a phone are most commonly used. Despite some limitations, 2FA is a valuable way to use popular services and applications more securely.