The SMS text message verification method of authentication is actually quite straightforward. A text message with an SMS authentication code is sent to the user after they sign in. To gain access, all they have to do is enter that code on the corresponding app or website. Amazon, Facebook, Google, Twitter, and other services probably make us go through this verification process when logging in.
SMS authentication verifies the identity of the user by using their handset. A login becomes more secure this way. That means an attacker would have to steal a user’s password and phone to gain unauthorized access to their account.
