Authy

Authy is a cloud authentication service exposed via an API. It is commonly used for the addition of two-factor authentication (2FA) to existing username and password logins. However it can also be used to replace the password for primary logins, as well as providing a robust and secure mechanism for the approval of high value transactions.

There are several features you can leverage to better authenticate users or authorization transactions in your application.

• Send a One Time Password via SMS
• Send a One Time Password via a voice call
• Generate a Time based One Time Password using the Authy app (iOS/Android/Chrome)
• Use a push notification with an approve/deny response to the Authy app or an SDK embedded in your app
• Validate a user has access to a phone number by validating a code sent via an SMS
• Validate a user has access to a phone number by validating a code sent via a voice call

Authy API

The Authy API is used inside applications to provide 3 different security use cases.

• Second factor of authentication (2FA) after another form of authentication (typically username & password). For example, using our free Authy application to generate a Time based One Time Password (TOTP).
• Primary authentication where common logins are secured with Authy using a device registered with username and password. For example, you no longer need the password, just the username at login and instead respond to a push notification request.
• Step up authentication or authorization of in application, high value transactions. For example sending a push notification request to a user's device, generating an approval for a financial transaction in a banking application.

The API is split into two main features:

• Time based One Time Password (TOTP) - OneCode & SoftToken
• Push notification based authentication - OneTouch

API Endpoints

The Authy API consists of four families of endpoints:

• TOTP API
  Create and verify two-factor authentication via SMS, voice calls or codes from the Authy app.
• Authy OneTouch API
  Create and verify approval requests that will show up on the Authy or custom mobile apps.
• Phone Verification API
  Verify a user's landline or cell phone by sending them a verification code.
• Phone Intelligence API
  Get information about a phone number, to tell if the number is voip, landline or cell phone, as well as carrier information.

Authy helper libraries

Authy, with the community, maintains a set of libraries which simplify the interaction with the API in specific languages.

• Ruby
• Python
• PHP
• Java
• .Net

Authy mobile apps

Software based two-factor authentication or primary authentication with Authy relies on using a free mobile or browser based application. We currently support the following platforms.

• Apple iOS
• Google Android
• Google Chrome