What Developers Need to Know About Multi-Factor Authentication

10/24/2022 Jing Gu

Developers are always looking for ways to make users' lives easier. But when it comes to security, sometimes making things easier for users can have the opposite effect. Take multi-factor authentication (MFA), for example. Requiring users to jump through the extra hoop of a second factor is often detrimental to the user experience but improves the security of your application.

Google's 2021 authentication and password management best practices report showed that introducing multiple authentication factors can significantly reduce the likelihood of an account being hacked. (Google)

The good news is, MFA can be implemented without being detrimental to a seamless user experience. As developers, we might be tempted to write off MFA as yet another burden, but it's relatively easy to implement. In this blog post, we'll discuss MFA, why you need it, and how to implement it. You'll soon be ready to step up your authentication game and keep your users' data safe and sound.

What is MFA?

MFA stands for Multi-Factor Authentication, a type of security system that requires multiple authentication methods from a series of credentials to verify a user's identity. This makes it more challenging for someone to gain unauthorized access to a system or account because they'd need to possess multiple types of information. 

For example, if a user tries to log into their bank account, they'll typically receive a username, and password prompt, followed by a code sent to their phone number. To successfully log in, the attacker must have all of both a password and a code. 

Side note: it's important to understand the difference between authentication and authorization. Check out our helpful guide to learn more.

MFA is often referred to as two-factor authentication (2FA) or two-step verification. These terms are used interchangeably and refer to the same concept.

When setting up MFA, it is important to strike the right balance between security and usability. For example, if the MFA process is too complicated, users may be tempted to disable it or work around it, defeating the purpose of having it in the first place. On the other hand, systems and data are left vulnerable to attack if MFA is not used at all.

Why do you need it?

These days, passwords just don't cut it anymore. In addition, hackers are becoming more sophisticated, and they have a variety of methods for stealing passwords. Once they have a password, they can easily access sensitive data such as credit card numbers or personal information. 

If you have MFA in place, when a hacker manages to steal a password, they will be unable to access the account without the second factor. As a result, MFA dramatically reduces the risk of data breaches and protects your users' information. 

Not all MFA is created equal

It's important to remember that not all MFA methods are created equal. Legacy MFA often utilizes phishable or easily stolen factors. SMS-based codes are the most common form of MFA, but they have several well-documented security flaws. Using legacy MFA that leaves a password in place as a factor can also make an account more vulnerable to an attack, as we've seen with the recent rash of SIM swapping attacks.

When implemented correctly, multi-factor authentication can be a powerful tool in the fight against online fraud and account hijacking. However, it's important to remember that MFA is not a silver bullet and must be used in conjunction with other security measures to be truly effective. An MFA best practice is to use strong authentication factors that cannot be phished such as local device biometrics, cryptography keys, and hardware security keys. 

There are several types of credentials used as part of MFA, but the most common are listed below:

  • Something you know: an answer to a security question, a PIN, or a password.
  • Something you have: A physical token like a key fob or a smartphone authenticator app.
  • Something you are: This is usually your face, fingerprint, signature, voice or an iris scan.

Of these three factors, the knowledge factor is the weakest as it can be guessed, stolen, or phished. MFA can be any combination or all of these factors.

How to Implement Multi-Factor Authentication

Fortunately, implementing MFA is easier than it might seem. There are multiple ways to add MFA to your application, so you can choose the method that makes the most sense for your particular use case. Before you start, though, here are four steps you can implement to ensure successful implementation of MFA:

  • Plan: Consider the systems and features that need MFA protection and how users will access them. Map out the user journey across every authentication point.
  • Build: Select the MFA methods that will work best for your organization.
  • Test: Make sure that the MFA solution works as intended and that users can access the systems they need without any problems.
  • Monitor: Review MFA activity regularly to look for any suspicious behavior.

The first step is considering how MFA will complement your existing systems internally. You'll also want to think about how users will access these systems. For example, will they use a web browser or a mobile app? Will they need to authenticate every time they access the system or just when they perform specific actions?

Once you've determined which systems need MFA protection, you can select the methods that will work best for your organization. There are various MFA solutions on the market, so choosing one that meets your needs is important.

Once you've selected an MFA solution, you'll need to test it to ensure it works as intended. This includes testing the various authentication methods to ensure users can access the systems they need without any problems.

Finally, you'll need to monitor MFA activity regularly. This makes it easier to identify any suspicious behavior and take steps to prevent it. At this stage, if you find users having difficulty using the MFA solution, you may need to change how it's implemented.


As you can see, multi-factor authentication offers an extra level of security that is definitely needed when a new attack is in the news every few days. While there are different ways to implement MFA, not all factors are created equal in terms of security and usability.

Beyond identity provides SDKs that allow you to implement unphishable MFA without adding any additional steps for the end-user:. You can get started with a free developer account: https://www.beyondidentity.com/developers/signup