What is authentication?

Authentication is the process of verifying the identity of a user or device, answering the question: "Who are you?"

In simple terms: authentication confirms that you really are who you claim to be.

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#Why authentication is needed

Without authentication:

• anyone could pose as someone else;
• accounts and systems cannot be protected;
• access control does not work.

Authentication is needed to:

• protect accounts;
• restrict access to systems;
• ensure the security of data and services.

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#Examples of authentication

You go through authentication when you:

• enter a login and password;
• enter a code from an SMS or an app;
• use a fingerprint;
• log in with a certificate or a token.

Entering a password is the simplest and most common example.

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#Authentication factors

Authentication is usually based on factors:

#1. Something you know

• a password;
• a PIN code.

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#2. Something you have

• a phone;
• a token;
• a smart card.

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#3. Something you are

• a fingerprint;
• a face;
• a voice.

The more factors, the higher the security.

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#Types of authentication

#Single-factor (1FA)

• password only;
• the least secure.

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#Multi-factor (MFA)

• two or more factors;
• significantly increases protection.

MFA is the standard of modern security.

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#How authentication differs from authorization

Important for interviews.

• Authentication is who you are
• Authorization is what you are allowed to do

Authentication always comes first, then authorization.

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#Which security properties it supports

• Confidentiality - protection against unauthorized access;
• indirectly - Integrity.