Implementing Authentication in Node.js

Authentication is a fundamental aspect of any web application, ensuring that users can securely log in and access sensitive resources. In Node.js, authentication requires securely handling user credentials, validating access rights, and managing sessions effectively. To achieve this, developers commonly rely on two key techniques: hashing passwords for secure storage and using JSON Web Tokens (JWT) for stateless authentication.

Together, password hashing and JWTs form a robust foundation for building secure, efficient, and scalable authentication systems in Node.js applications.

Password hashing with bcrypt

Passwords should never be stored in plain text to ensure user security. If a database is compromised, plain-text passwords can be easily exploited, putting all accounts at risk. Instead, passwords should be hashed, transforming them into irreversible strings that cannot be converted back to their original form.

The bcrypt library is a reliable tool for hashing passwords in Node.js. It adds a unique random string, called a salt, to each password before hashing, ensuring that even identical passwords produce different hashes. This approach prevents attackers from using precomputed hash dictionaries, making it much harder to crack passwords. In addition to hashing passwords during registration, bcrypt allows for secure verification during login by comparing the entered password with the stored hash. This ensures user credentials are protected even if the database is compromised.