Authentication and Authorization Explained

Key Concepts

• Authentication
• Authorization
• Credentials
• Multi-Factor Authentication (MFA)
• Role-Based Access Control (RBAC)
• OAuth
• OpenID Connect
• JWT (JSON Web Tokens)
• Access Control Lists (ACL)
• Session Management

Authentication

Authentication is the process of verifying the identity of a user or system. It ensures that the user is who they claim to be. Common methods include passwords, biometrics, and digital certificates.

Example:

When you log into a website using your username and password, the site is authenticating you to confirm your identity.

Authorization

Authorization is the process of granting or denying access to resources based on the authenticated user's privileges. It determines what actions the user is allowed to perform.

Example:

After logging into a banking app, you are authorized to view your account balance but not to transfer funds unless you have the necessary permissions.

Credentials

Credentials are the pieces of information that authenticate a user's identity. These can include passwords, PINs, security tokens, or biometric data.

Example:

A username and password combination is a common set of credentials used to authenticate a user.

Multi-Factor Authentication (MFA)

Multi-Factor Authentication (MFA) is a security process that requires users to provide two or more verification factors to gain access. This adds an extra layer of security beyond just a password.

Example:

After entering a password, a user might also need to enter a code sent to their mobile phone to complete the login process.

Role-Based Access Control (RBAC)

Role-Based Access Control (RBAC) is a method of regulating access to resources based on the roles of individual users within an organization. Each role is assigned specific permissions.

Example:

In a company, an "Admin" role might have full access to all resources, while a "Guest" role might only have read-only access.

OAuth

OAuth is an open standard for access delegation, commonly used as a way for users to grant websites or applications access to their information on other websites without giving them the passwords.

Example:

When you use your Google account to log into a third-party app, OAuth is used to grant the app access to your Google data without sharing your password.

OpenID Connect

OpenID Connect is an authentication layer built on top of OAuth 2.0, which allows clients to verify the identity of the end-user based on the authentication performed by an authorization server.

Example:

A website can use OpenID Connect to authenticate users through a third-party identity provider like Google or Facebook.

JWT (JSON Web Tokens)

JWT (JSON Web Tokens) are a compact, URL-safe means of representing claims to be transferred between two parties. They are commonly used for authentication and information exchange.

Example:

After logging in, a server might issue a JWT to the client, which the client then uses to authenticate subsequent requests.

Access Control Lists (ACL)

Access Control Lists (ACL) are a list of permissions attached to an object. Each entry specifies which users or system processes are granted access to objects, as well as what operations are allowed on given objects.

Example:

An ACL for a file might specify that User A has read and write permissions, while User B only has read permissions.

Session Management

Session Management involves creating and maintaining user sessions after successful authentication. It ensures that the user remains authenticated until they log out or the session expires.

Example:

After logging into a website, a session is created, and a session ID is stored in a cookie. This session ID is used to authenticate the user for the duration of their visit.

Examples and Analogies

Think of Authentication as showing your ID at the entrance of a building. Authorization is like having a keycard that allows you to access certain rooms within the building. Credentials are the ID and keycard you use. Multi-Factor Authentication is like needing both your ID and a fingerprint scan to enter. Role-Based Access Control is like having different keycards for different roles (e.g., employee vs. manager). OAuth is like giving a delivery person a temporary key to drop off a package. OpenID Connect is like using your building ID to access multiple buildings. JWT is like a digital keycard that expires after a certain time. Access Control Lists are like a list of who can enter which rooms. Session Management is like keeping your keycard active until you return it at the end of the day.