Two-Factor Authentication

Authentication is the verification of the authenticity of something, for example, checking the entered password by comparing it with the one specified during registration.

Password today is the most popular access protection tool, but even a very strong password is vulnerable, which is why many services and programs offer, in addition to a password, to use some form of additional protection.

In general, authentication does not necessarily have to be double; it can also be triple: for example, first you enter a permanent password, then you receive a one-time password via SMS, and then you must also confirm a fingerprint.

The presence of two-factor authentication depends on the service or software being used: you cannot use it where it is not implemented by the developer. Moreover, two-factor authentication can vary; in this chapter, we will discuss the most popular methods.

Key File

Some programs offer to use a key file in conjunction with a password. A key file is a protection tool where the program requires you to provide a specific file for authorization.

This option is used in the popular encryption program TrueCrypt and its fork VeraCrypt. When creating a container, you specify a file, and subsequently, for decryption, the program will require you to provide that file.

Almost any file can be used as a key file, and the file will remain intact. But remember that you cannot make any changes to this file; otherwise, its structure will change, and it will stop working. It is also not advisable to use excessively large keys, as this is pointless: VeraCrypt, for example, uses the first 1024 kilobytes of the file.