Authentication

Contents

• What is authentication
• Differences between authentication, identification, and authorization
• Types of authentication
• Methods of authentication
• Multifactor authentication

What is authentication

Authentication is the process of verifying the identity of a user or a system. This term is most commonly used in the field of information technology. A classic example of authentication is comparing the password entered by the user with the password stored in the server's database. The authentication process is critically important for controlling access to various services and resources, thereby ensuring information security.

Differences between authentication, identification, and authorization

To better understand the relationship between authentication, identification, and authorization, let's consider the example of logging into a social media account, such as VKontakte, from a new device:

1. You open the website and enter your username and password — this is the identification process, where the system recognizes you as a user.
2. After clicking the "Log In" button, the system compares the entered data with what is stored on the server. If the data matches, you have been authenticated.
3. If you have two-factor authentication enabled, an SMS with a code will be sent to your phone. After entering this code, the system confirms your identity and allows you to log into your account.
4. Access to your account and data, such as photos and privacy settings, is the process of authorization.

Types of authentication

Authentication can be classified according to various criteria, including the number of methods and subjects of verification:

By the number of methods:

• Single-factor authentication: One method of confirmation is used, such as a password.
• Multifactor authentication: A minimum of two methods of confirmation is required, such as a password + a one-time code or a password + biometric data.

By the number of subjects of verification:

• Unidirectional: Only the user verifies their authenticity to the server.
• Mutual: Both the user and the server verify each other's authenticity, which is especially important for confidential data.

Methods of authentication

Methods of authentication can vary depending on the type of resource, network structure, and technologies used for recognition. Authentication levels can be divided by the degree of confidentiality:

• Non-sensitive data: A leak of such data does not lead to serious consequences. A reusable password is sufficient.
• Internal data: A leak can lead to significant losses. Stricter authentication is required, such as one-time passwords.
• Confidential data: Access to such data requires multifactor authentication.

Multifactor authentication

Multifactor authentication (MFA) involves using more than one method of confirmation to access data. These methods may include:

• Something you know: Information known only to the user (e.g., PIN code, password).
• Something you have: A physical object belonging to the user (e.g., token, magnetic card).
• Something you are: Biometric data unique to the user (e.g., fingerprints, facial recognition).

One common example of multifactor authentication is two-factor authentication (2FA), which requires confirmation using two different methods. When attempting to log in from a new device, the user may be prompted to enter a code received via SMS or through a special application.