Every time, when you try to access data and resources from the server, a web-authentication process goes behind the scene. The authentication process is to prove that you are the authenticated user who has the permission to access data. The process simply adds security to your data.
Basics of Authentication:
Whenever you try to exchange data, the client and server exchange certificates that is must set up a secure line to pass credentials. Once your credentials are accepted, you can encrypt data. Both SFTP and FTPS protocol transfers use asymmetric encryption method. In this process, the public key is combined with a unique encrypted key that is private along with the data that is being transferred. Thus, public key and private key both work together in a pair. As long as your private key is secured, the process of data transfer is also secured. Only the owner is able to decrypt a private key.
The easiest and convenient way of authentication is software based single-factor authentication. From creating public and private keys to transferring data, all the activities are controlled or handles either by the software that is installed on your computer system or on the server. Both private and public keys are stored in hidden locations or encrypted ( or both). But hackers are very expert in hacking the systems and internet servers. It is not an impossible job for them to breach internet security.
Two-factor web authentication is answers to the problem. In addition to a usual password, users need to provide a physical form of proof to authenticate themselves. Even if the credentials are right, the physical factor making it difficult for hackers to access a resource. The method is very helpful for enterprises where single factor authentication is not enough secure. Two-factor authentication systems use mobile phones, biometrics or any other private physical thing as second factor. Only the authenticated user has the permission to access such devices. So, the system is highly secured and safe.