Authentication Methodologies

Building secure applications requires robust user authentication. Let's look at different ways to authenticate users and understand when to use each method.

Password-based authentication is the most common method. Users provide a username and password which is checked against stored credentials. While simple to implement, this method has limitations. Users often choose weak passwords or reuse them across sites. To make password authentication more secure, you can add requirements for password complexity and implement rate limiting to prevent brute force attacks.

Two-Factor Authentication (2FA) adds an extra layer of security. After entering their password, users must provide a second form of verification. This could be a code sent via SMS or generated by an authenticator app. 2FA significantly improves security because even if attackers steal a password, they can't access the account without the second factor.

Token-based authentication uses temporary access tokens instead of sending credentials with every request. When users log in, they receive a token (usually a JWT) that they include in subsequent requests. Tokens can contain user information and permissions, and they automatically expire after a set time. This makes token-based auth ideal for modern web applications and APIs.

OAuth is used for authorizing applications to access user data on other platforms. For example, when you "Login with Google," you're using OAuth. The application gets a token to access your Google data without ever seeing your Google password. OAuth is perfect when you want to integrate with other services or provide "Sign in with X" functionality.