Salt in Cryptographic Hashing: Best Practices
Written by  Daisie Team
Published on 8 min read


  1. What is a cryptographic hash?
  2. What is salting in cryptography?
  3. Why salting matters in cryptographic hashing
  4. How to implement salting in hashing
  5. Best practices for using salt in hashing
  6. Common mistakes when salting hashes
  7. How to secure your hashes with salt

Imagine you're trying to keep something valuable safe. You could hide it, but what if someone stumbles upon it by accident? Instead, you might place it in a box and lock it. That's essentially what a cryptographic hash does in the realm of cybersecurity. But, there's more to it. To truly fortify the lock, you need to understand salt in cryptographic hashing. In this blog, we'll explore cryptographic hashes, the role of 'salt' in them, how to properly use it, and common mistakes to avoid. So, let's dive into this fascinating world of cryptography!

What is a cryptographic hash?

Think of a cryptographic hash as a unique digital signature for any set of data. No matter how big or small the data is, a cryptographic hash always transforms it into a fixed size. Always! Here's something interesting — even a minor tweak in the data results in a completely different hash. The beauty of cryptographic hashes is that they're a one-way street. Once you've transformed your data into a hash, it's impossible to reverse the process.

The function that performs this transformation is called a hash function. Hash functions are like chefs cooking up a dish. You give them ingredients (your data), and they cook up a hash. But unlike chefs, hash functions use the same recipe every time. This means, if you give them the same data, you'll get the same hash. Now that's what I call consistent!

There are many hash functions out there, like SHA-256, MD5, and others. But not all hash functions are created equal. Some are stronger and more secure than others. For example, MD5 has known vulnerabilities, while SHA-256 is currently one of the most secure hash functions. But as with everything in cybersecurity, nothing is foolproof!

Now that we understand what a cryptographic hash is, we can move on to the next big thing — salting in cryptography. By adding a pinch of 'salt', we can make our hashes even more secure. But more on that later!

What is salting in cryptography?

Remember when we said hash functions are like chefs? Well, imagine what would happen if you gave the same recipe to a hundred chefs. They'd all cook up the same dish, right? That's a problem in cryptography. If everyone uses the same hash function, hackers could eventually figure out what data creates what hash. To avoid this, we add a little 'salt' to our data before hashing it. So, what exactly is this 'salt'?

Simply put, 'salt' is a random piece of data that we add to our original data. It's like adding a secret ingredient to our recipe. This makes our hash unique, even if others are using the same hash function. The salt is usually stored along with the hash, so we can verify the data later.

Here's an example to help you understand salt in cryptographic hashing. Let's say we have the password '12345'. When hashed with a function like SHA-256, it will always produce the same hash. But if we add a salt, let's say '67890', to the password before hashing it, we'll get a different hash. Even better, if we use a different salt each time, we'll get a different hash each time, even though the password is the same. Now isn't that something?

Adding salt to our hashes makes them more resistant to attacks. It's like changing the locks on your doors regularly. Even if a thief copies your key, they won't be able to use it for long. But like everything in cryptography, salting needs to be done right. We'll talk about the best practices for salting in a bit.

Why salting matters in cryptographic hashing

Now that we've got a handle on what salt is in cryptography, let's talk about why it's important. You might be thinking: "Sure, salt makes my hashes unique, but do I really need to use it?" The answer is a resounding yes, and here's why.

Imagine someone gets their hands on a list of hashed passwords. If these hashes are unsalted, all they need to do is run commonly used passwords through the same hash function and see if they match any in the list. This is known as a 'rainbow table' attack.

But wait, what if we added salt to our passwords before hashing them? Well, the attacker would need a different rainbow table for each salt. And since salts are typically random and unique for each user, this makes things exponentially harder for the attacker. It's like they have to crack a different lock for each door, instead of using the same key for all.

This is why understanding salt in cryptographic hashing is so important. It's not just about making your hashes unique, it's about making them secure. Without salt, your hashes could be as vulnerable as a fortress with one key for all its doors. And we all know how that story ends, don't we?

How to implement salting in hashing

So, we've established that salt is like the secret ingredient to a secure hash. But how do we actually use it? Don't worry, it's not as hard as it sounds. Let's break it down into some simple steps.

First things first, you need to create your salt. This should be a random string of characters, and it should be unique for each user. There are many ways to generate a salt, but one common method is to use a function that generates a random string of a certain length. This is your salt - your secret ingredient.

Next, you combine the salt with the password. This can be as simple as appending the salt to the end of the password. But remember, the order matters here. If you add the salt before the password, it's called a 'salt prefix'; if you add it after, it's a 'salt suffix'. Either way, the result is a unique input for each user.

Now, you're ready to create your hash. You take the combined salt and password, and pass it through your hash function. The result is a unique, secure hash that's ready to be stored in your database.

And there you have it! That's all it takes to understand and implement salt in cryptographic hashing. With these steps, you're not just creating hashes - you're building a fortress, one secure hash at a time.

Best practices for using salt in hashing

Just like any recipe, the key to a successful salted hash lies not only in the ingredients but also in the method. So, let's talk about best practices for using salt in hashing, shall we?

Firstly, remember that your salt should be as unique as a snowflake. Each user should have their own salt. Why, you ask? Well, if two users have the same password and the same salt, they'll end up with the same hash. And we don't want that. Each hash should be as individual as the user it represents.

Also, size matters when it comes to salt. A longer salt means a greater number of possible hash outputs, making it harder for attackers to guess. So, don't skimp on your salt length - go for at least 16 characters if you can.

Next, don't forget to keep your salt secret. Just like the Colonel's secret blend of herbs and spices, your salt should be known only to you. Store it securely, separate from the hash, and never ever share it. Remember, the salt isn't just part of the hash, it's part of your security strategy.

Finally, always remember that salt is not a one-and-done deal. Regularly update your salt, just like you would your password. This keeps things fresh and keeps attackers on their toes. Regular salt changes are a great way to add an extra layer of security to your hashes.

And that's it! If you follow these best practices, you'll be well on your way to understanding how to use salt in cryptographic hashing effectively. Keep your salt unique, lengthy, secret, and fresh, and your hashes will be as secure as they can be.

Common mistakes when salting hashes

Alright, we've talked about best practices. Now, let's flip the coin and explore some common slip-ups people make when they're trying to understand salt in cryptographic hashing. By learning about these pitfalls, we can better avoid them, right? So, let's dive in!

One of the biggest mistakes people make is using the same salt for all users. Just like you wouldn't use the same key for every door, you shouldn't use the same salt for every hash. Doing this makes it easier for attackers to guess your hashes. So, remember: one user, one salt. Simple, right?

Another common misstep is not storing salt securely. If an attacker gets their hands on your salt, they're halfway to guessing your hash. So, treat your salt like a secret ingredient in your grandma's secret recipe. Keep it hidden, keep it safe!

Not using a long enough salt is another mistake to watch out for. The longer the salt, the harder it is for attackers to guess your hash. Think of it like this: a longer password is harder to crack than a shorter one, right? The same principle applies to salt. Don't shortchange yourself—make your salt lengthy!

Finally, many folks make the mistake of not regularly updating their salt. Just as you update your passwords, so too should you update your salt. This keeps things fresh and adds another layer of security to your hashes. So, remember to change your salt like you change your socks—regularly (hopefully).

By steering clear of these common mistakes, you'll be well on your way to effectively understanding and implementing salt in cryptographic hashing. Remember, a little bit of knowledge goes a long way in the world of cryptography!

How to secure your hashes with salt

So, you're all set with understanding salt in cryptographic hashing, and you're aware of the common mistakes to avoid. Now, let's get down to the nitty-gritty: how do you actually secure your hashes with salt? Let's break it down into straightforward, manageable steps.

Firstly, create a unique salt for each user. Remember what we said about not using the same key for every door? Well, the same goes for salt. Every user should have their own unique salt. This makes it much harder for anyone trying to guess your hashes.

Next, securely store your salt. Treat it like a top-secret document—it should be stored safely and securely. This is a critical step in securing your hashes. If someone gets hold of your salt, they've got half the puzzle solved. So, keep it under lock and key!

Also, make sure your salt is long enough. The longer the salt, the harder it is for someone to guess your hash. You wouldn't set your password as '1234', right? So, don't cut corners with your salt length. Make it as long as possible.

Lastly, update your salt regularly. Just as you would change your passwords from time to time, the same should go for your salt. This adds an extra layer of security, and keeps your system fresh and up-to-date.

By following these steps, you'll be well on your way to securing your hashes with salt. Remember, when it comes to cryptography, every little bit of precaution helps. So, take your time and do it right. Happy hashing!

If you're interested in learning more about the importance of salt in cryptographic hashing and how it ties into the broader world of digital security, check out the workshop 'Crypto For Creators, Part 1: The Backbone Of The Digital Economy' by Tom Glendinning. This workshop will provide you with valuable insights into digital security best practices, ensuring that your creations are safeguarded in the ever-evolving digital landscape.