One-time passwords from SMS, which are usually used for two-step authentication (2FA) to any services, are not secure. They can be spied on or intercepted. The most reliable alternative is authenticator apps.
How Authenticator Apps Work :
- Install the application on your smartphone.
- In the service's security settings, find the option to enable two-factor authentication.
- Choose two-factor authentication using the app.
- The service will display a QR code that can be scanned in a 2FA application.
- Scan the code by the application and it starts generating a new one-time code every 30 seconds.
One-time codes are synchronously generated and synchronized based on a key that is known only to your device and server, as well as the current time, rounded up to 30 seconds. This algorithm is called OATH TOTP (Time-based One-time Password).
Typically, two-factor authentication applications work with the same algorithm, so they can be used in almost any service. In this article, I have identified two of the most popular and convenient, as well as one alternative.
Google Authenticator
Google Authenticator is a free 2FA app from Google for iOS and Android users.
Download: Google Authenticator for Android
Twilio Authy 2-Factor Authentication
Authy is an alternative to Google Authenticator for iOS and Android. Authy has the advantage over most 2FA app options - you can sync your accounts across multiple devices.
Usually, if you want to change your smartphone, then you need to back up the settings and transfer data about your 2FA application manually. This can take a long time. Also, if someone steals your phone, your codes and 2FA accounts will be gone. Authy fixes this problem with a secure backup system. This means you can transfer your Authy 2FA accounts between devices.
Download: Authy for Android
