Lesson Goal
To explain the concept of ‘salting’ in cryptography, its purpose in enhancing security, and its role in password protection.
Salting is a cryptography technique used to safeguard passwords stored in a database. It involves adding a unique, random string of characters known as a ‘salt’ to each password before hashing. This process enhances security by ensuring that even identical passwords will result in different hash values.
Understanding Salting:
- Hashing Basics: Hashing is a process where a string of data (like a password) is converted into a fixed-size value or key. While hashing is a one-way process and generally secure, it’s vulnerable to brute force attacks and precomputed tables like Rainbow Tables.
- Role of Salting: Salting adds an extra layer of protection. By appending a unique salt to each password before hashing, it ensures that the resulting hash is unique even if the original passwords are the same.
How Salting Works:
- Unique Salts for Each User: Each user’s password gets a unique salt. The salt and the password are concatenated and then hashed.
- Storage: The salt must be stored in the database alongside the hashed password. It’s not meant to be secret; its purpose is to be unique.
- Verification Process: When a user logs in, the stored salt is added to the entered password, and the combination is hashed. This hash is compared with the stored hash to verify the user’s identity.
Benefits of Salting:
- Thwarts Rainbow Table Attacks: Since each password hash is unique due to the salt, precomputed Rainbow Tables become ineffective.
- Increased Complexity for Brute-Force Attacks: Salting makes brute-force attacks more time-consuming and computationally expensive, as attackers must compute hashes for each password guess combined with each possible salt.
Best Practices in Salting:
- Use a Long, Random Salt: The salt should be sufficiently long and random to ensure its effectiveness.
- Unique Salt for Each Password: Every password should have a distinct salt. Reusing salts across multiple passwords diminishes the security benefits.
Summary: Salting is a critical security measure in password protection. It enhances the security of stored passwords by ensuring that even if two users have the same password, their stored password hashes will be different.
For an in-depth understanding of salting and its importance in cryptography, refer to the Wikipedia page: Salt (Cryptography) Wikipedia.