Outerband authentication is multi-factor authentication( MFA), a combination of two-factor authentication( 2FA) and single-factor authentication. 2FA authentication uses the transmission channel over which the signal is also transmitted, whereas SFA authentication has its own secondary communication channel.
Out-of-band authentication fulfills a higher level of security compared to normal MFA authentication, which uses a transmission channel. The two transmission channels used in out-of-band authentication operate completely separately and are not directly dependent on each other. This technique significantly increases security and makes it more difficult for attackers to access sensitive data. For example, 2FA technology can be used to transmit two verifications such as a password and a personal identification number, and the out-of-band channel can be used to transmit a biometric feature such as a voiceprint for voice recognition.