Password Hashing

Password hashing is a security technique that converts a plain-text password into a unique, fixed-size string of characters, making it difficult to reverse-engineer.

Password hashing is a crucial method used to protect stored passwords from being exposed in the event of a data breach. Unlike encryption, which can be decrypted, hashing is a one-way function that converts a password into a fixed-size string of characters, known as a hash. Each time a password is hashed, it produces the same output, but the process is designed to be irreversible, meaning you cannot easily derive the original password from the hash.

When a user creates a password, it is hashed and stored in the database. During login, the entered password is hashed again and compared to the stored hash. If the hashes match, access is granted. To further enhance security, a “salt” is often added to the password before hashing. This is a random value that ensures even identical passwords will have different hashes, protecting against attacks that use precomputed hash databases, known as “rainbow tables.”

Password hashing algorithms, such as bcrypt, scrypt, and Argon2, are specifically designed to be computationally expensive, making it difficult for attackers to perform brute force attacks. These algorithms are preferred over general-purpose hashing functions like MD5 or SHA-1, which are faster but less secure due to vulnerabilities.

Implementing strong password hashing practices is critical for any system that stores user credentials. It reduces the risk of password leaks and helps comply with data protection regulations. Even in the unfortunate event of a data breach, hashed passwords, especially when combined with salts, significantly increase the security of user data.