2FA - Two Factor Authentication

Two Factor Authentication - sometimes abbreviated as 2FA or TFA - is an additional level of security for applications that's designed to prevent anyone from accessing an account, even if the username and password combination has become known.

In addition to identifying a user by their email and password, they are also asked to provide a second piece of identification. In this case that is a number, which proves they have a device with them. The ‘first’ factor is their password, and the ‘second’ factor is this number. The number is typically generated by an app they have on their phone.

The number changes regularly, and the same number can only be used once (so someone cannot note down the number and use it again later). Such single-use numbers are called One Time Passwords (OTP). The fact each number can only be used once provides the added security, as it prevents an eavesdropper from using it at a later date.

 

clearString supports both TOTP and HOTP open standards – RFC6238 and RFC4226 respectively.

Read more about implementing 2FA/TFA...