Hashing & Salting | CompTIA Security+ 701

In the world of digital security, particularly when it comes to protecting passwords and sensitive data, hashing and salting are two critical techniques used to ensure that information remains safe. You might have heard these terms before, especially if you're into tech, but they might still sound confusing. Don’t worry, we’ll break it all down in simple, easy-to-understand language, with examples to make things clearer.

What is Hashing?

Defining Hashing

Hashing is a process of converting any input (like a password, a file, or a piece of data) into a fixed-length string of characters, which is usually a sequence of numbers and letters. This string is known as a hash or hash value.

The key point to understand here is that the output (the hash) is always the same size, no matter how large or small the input is. For example, no matter if you hash a short word like "dog" or a long paragraph of text, the output hash will always be a fixed size.

Example of Hashing

Let’s say you have the word "apple". When you apply a hashing algorithm like SHA-256 (one of the most common hashing algorithms), it will produce a hash value like this:

1f3870be274f6c49b3e31a0c6728957f

If you change the word slightly, say to "ApPle" (case-sensitive), the hash will change dramatically:

3d4a8be1be0b292010b38b350410d3ff

Why is Hashing Important?

• Data Integrity: Hashing ensures that data hasn’t been tampered with.
• Password Storage: Websites store the hash of the password instead of the actual password.
• Digital Signatures: Hashing is used to verify the authenticity of documents.

What is Salting?

Defining Salting

Salting is a technique used to further secure the process of hashing, especially when dealing with passwords. A salt is a random value that is added to the password before hashing it.

Example of Salting

Let’s take the password "password123". If we hash this password using SHA-256 without a salt, it will always produce the same hash:

ef92b778bafe771e89245b8e1e9e2ab23d2db2e7db4fe4b4003a5a7988c703d8

But if we add a random salt to it, like "7F9s8d", and then hash the combination, we get a completely different hash:

a3f465fd3fd07d2b46246f5353f59a43b7f0c4ab66036d218d88c32093993949

Why is Salting Important?

• Prevents Rainbow Table Attacks: Salting makes precomputed hash tables useless.
• Improves Security for Common Passwords: Even identical passwords will have different hashes.
• Defends Against Brute Force Attacks: Each password has a unique salt, making cracking harder.

How Hashing & Salting Work Together

1. A user creates an account and chooses a password.
2. The website generates a random salt for the user.
3. The password is combined with the salt and hashed.
4. The salt and hash are stored in the database.
5. When logging in, the system hashes the input password with the stored salt and compares it to the stored hash.

Conclusion

In summary, hashing and salting are fundamental techniques in digital security. Hashing transforms data into a fixed-size string, while salting adds randomness to make the process more secure. Together, they ensure that even if hackers breach a system, they cannot easily obtain usable information.