Every year we see more and more high-profile data breaches. In 2019, companies reported over 3,800 data breaches, and 4.1 billion records were accessed. These included records from major financial institutions.

With so much of our daily lives and business transactions occurring online, cybersecurity threats can be devastating for customers and costly for corporations. Thus, there’s been a push towards improving cybersecurity in recent years. Two-factor authorization (2FA) is one standard method for cybersecurity.

In the past, new security features meant much extra work for application developers. Now, that’s not the case. There are many APIs on the market to help add 2FA into your applications. We’ve reviewed some of the best ones below. But first, let’s take a look at 2FA to get a sense of how it works.

What Is Two-Factor Authentication?

The idea around 2FA is simple. Two-factor authentication is an added level of security in addition to your password. It’s a way to verify that you are who you say you are, often involving some external cue.

Most identity specialists define two-factor authentication as involving two of any of these three attributes:

• Something the user knows: Such as a password or PIN.
• Something the user has: Such as a mobile phone, smart code, or token.
• Something unique to the person: Biometrics, such as a fingerprint.

You encounter 2FA when an app texts you a numeric token to enter as proof of identity. 2FA may involve push notifications on a separate device or email account. You might not think much of two-factor authentication as you see it so regularly, but that doesn’t mean it’s not important.

For consumer-facing web applications, one of the most common methods of implementing 2FA is via an SMS text. This is the method we’ll largely focus on, as it’s relatively easy for an API to send a text message automatically. We’ll also take a look at other methods for 2FA, to help you get an idea of what’s out there.

8 APIs For Two-Factor Authentication

Now, let’s delve into the APIs for two-factor authentication themselves.

Authy by Twilio

As one of the leading providers of voice, text, and SMS APIs, Twilio naturally provides a two-factor authentication API. Authy by Twilio offers nearly every form of two-factor authentication you could hope for.

Authy provides SMS authentication and features push notifications for situations where a customer’s phone might not be online. It also features one-time passwords (OTP) and time-based one-time passwords (TOTP) for situations where your customers might not even be able to receive a push notification.

Authy comes configured for over 200 different regions, as well. If you’re looking for an out-of-the-box solution for securing your app or website almost anywhere in the world, Authy by Twilio is a good choice.

Verify API by Vonage

Vonage (previously Nexmo) is a voice, phone, and SMS messaging platform, so it makes sense they’d also offer a two-factor verification API. Verify API is a relatively barebones 2FA API. It’s got several perks that make it worthy of consideration for your security needs.

First and foremost, Verify can be run in virtually any development environment. The Verify API has pre-written code for everything from curl to Node.js to Python or Ruby. This alone makes Verify a Swiss Army Knife for any 2FA applications you might have.

Verify is also available as an SDK so that you can integrate its security features into your products as well. Additionally, Verify features custom 2FA templates, allowing you to customize the authentication messages. This makes it even more useful for adding 2FA to your products or services.

Finally, Verify only charges you for what you use. At the time of writing, the API charges you $.0551 for each successful verification.

FortyTwo Two-Factor Authentication API

FortyTwo’s Two-Factory Authentication API is similar to the 2FA APIs we’ve already covered. However, it has a couple of unique features that make it stand out.

First and foremost, FortyTwo’s Authentication API has all the typical features you need for two-factor authentication. It can be used for standard security measures, like being asked a security question or to enter a PIN. It can also send temporary passwords and one-time temporary passwords via SMS. The end-user can also use biometric information for authentication, like a fingerprint.

The main thing that separates FortyTwo from other 2FA APIs is the ability for users to configure. The Sender ID can be configured, for one thing. It also delivers a call-back URI for delivery reports. Each authentication request produces a transaction ID, as well.

FortyTwo’s two-factor authentication doesn’t have monthly fees, either, so you pay for what you use. All of these factors, together, make FortyTwo’s API a solid choice for a well-rounded 2FA API.

Curity Authentication Service

If you’re looking for advanced multi-factor authentication (MFA) with a wide array of use cases that go beyond typical 2FA, consider the Curity Identity Server.

The Curity Authentication Service contains a whopping 25+ built-in authentication methods. This means applications can authenticate user identity by social login, SMS with Hyperlink, SMS One Time Password, Google Authenticator, BankID, and many other identity standards. Curity also provides an SDK to build your own solutions.

The Curity Server also boasts other features, like delegated identity with Single Sign-On (SSO). This can be completely white-labeled as your brand, another benefit for customizability. Curity Authentication Service enables developers to customize and chain authentication methods as needed; a robust identity framework that suits many application needs.

Curity Identity Server enables multiple authentication methods (authenticators), connected to various databases.

Disclaimer: Curity is a Nordic APIs sponsor.

Identity Automation

Identity Automation specializes in automating many business processes. They provide a 2FA API for automating authentication, as well. Identity Automation’s approach to multi-factor authentication mostly revolves around Rapididentity, their platform for Identity and Access Management (IAM). Rapididentity also offers multi-factor authentication via an API interface without the need for additional tools or customization.

Identity Automation offers many Identity and Access Management tools, from biometrics to QR codes to one-time passwords. That makes their API useful for very nearly any Identity and Access Management application you could think of. It also makes it easy to integrate and share information via Swagger, an OpenAPI platform for API design and documentation.

Auth0 API

Auth0’s multi-factor authentication API was born out of necessity. Auth0 started out as a simple multi-factor authentication app, allowing developers to add MFA to any app via a simple switch on Auth0’s dashboard. Their customers requested more control over the MFA process, however, leading the company to develop a fully-functioning API.

Auth0’s MFA API is a good choice for developers looking for a nearly plug-and-play API solution. It performs all of the basic 2FA, such as sending temporary passwords for SMS or email. Auth0’s API is useful for developers that need MFA solutions for multiple apps or digital properties. It allows you to easily integrate Single-Sign-On for one or more apps. It also ensures that JavaScript apps are secure, both front-end as well as mobile apps. Auth0’s API also protects your web apps via Security Assertion Markup Language (SAML).

One of the greatest strengths of Auth0 is the control over access to sensitive information. The API can generate alerts in the case of a data breach. It can also block the offending account. The API also makes it possible to set up MFA for when users want to access sensitive data. It also allows for advanced analytics to view who is accessing your API or website as well as when and from where they’re logging in from.

OneLogin API

OneLogin’s multi-factor authentication API is another simple-to-use API that is still customizable enough to be useful in a wide array of different applications.

OneLogin’s main application is for passwordless logins. One thing that differentiates OneLogin from other MFA APIs is the ability to log the user into other applications that are connected to OneLogin via a ‘session creation’ feature.

It also performs all of the standard 2FA functions you’ll need. These include temporary passwords sent via SMS or push notifications. It also helps keep your code as streamlined as possible via easy integration with Postman, a collaborative tool for API development. It eliminates the need to define multiple variables by using a simple ‘{{ }}’ command instead.

Authenticating.com API

Authenticating.com is a new suite of APIs that make it easy for developers to offer authentication for multiple applications. Authenticating.com’s API was designed specifically to allow developers to add authentication to their apps via a set of composite APIs, as well as an iOS and Android SDK.

Authenticating.com’s API is especially secure as it uses the same tools as the background check industry. Information is indexed for data integrity, adjudication, and policy enforcement.

Authenticating.com’s API offers a variety of tests to authenticate the user’s identity. Authenticating.com employs pre-made objects (User Objects, Check Upload Id Results, Test Result, and others). The statuses of which are reused within authentication methods. The platform boasts a wide variety of authentication methods (Verify Phone, Verify Email, SSN Verification, Verify ID, Verify Passport, and many others).

These features make Authenticating.com’s API a good choice for someone looking for out-of-the-box development solutions. As one of the newest 2FA APIs on the market, it offers some of the most features and is one of the easiest to use with transparent API documentation. It’s currently in the Beta Stage, at the time of this writing, but early reports look promising.

Final Thoughts

The number of high-profile data breaches continues to expand year after year. The need for cybersecurity is only going to become more intense as a result. Two-factor authentication is increasingly essential to ensure your digital assets are secure. Two-factor authentication APIs make setting up that security as automation and painless as possible.