In this article, we'll be briefly looking at what hashing entails and how it works. I have also included a link for you to check out this computing concept yourself, so stay with me until the end. Also, you wouldn't want to miss a fun fact about hashing!

What is hashing?

Hashing is simply the process of taking input data, passing it through a mechanism called a hash function, and then getting an output known as a hash value.

In a distributed peer-to-peer system like the Blockchain, you'll be working with a lot of transaction data, and because of this, you'll need a way to uniquely identify that data.

Think of it like this—there are approximately 8 billion people in the world today, and no two people have the same fingerprint. Because of this, fingerprints are unique to each individual and can be used to identify them.

In a similar way, hash values can be thought of as digital fingerprints for data. Just as fingerprints are unique to a person, hash values are unique to specific data and can be used to identify it.

How Hashing works

Let's say we want to hash some form of input data, like the word "computer". Now, we send this word through a hash function, which is a special mathematical formula or process. This function takes the input and performs several calculations to transform it into a fixed-size output, often a string of numbers and letters called the hash value.

This hash value is a unique representation of the input, and even a small change in the input will result in a completely different hash.

There are different types of hash functions and the differences between them come from the length of the hash values each function produces. A type of hash function used in a blockchain system is a cryptographic hash function, which can create digital fingerprints for any kind of data.

But why cryptographic hash functions? what makes it unique? Let's look at some of its properties:

Deterministic — This simply means that the same input always produces the same hash value. This makes sense, as every person in the world is uniquely mapped to a specific fingerprint. If there are any discrepancies in the hash value (output), they should be solely caused by discrepancies in the input data, not by the hash function.

Collision-resistant — No two persons have the same fingerprint and so, a cryptographic hash function minimizes the chances of two different inputs producing the same hash value.

Pseudorandom — Being Pseudorandom means that even a small change in the input leads to an unpredictable, completely different hash value. In other words, the resulting hash value should always be surprising and impossible to predict.

One way function — Using our fingerprint analogy once again, you can’t trace it back to the person who made it by simply looking at it. Similarly, a one-way function means you can’t reverse the hash value to find the original input data—it basically reveals nothing about the input.

Fast Computation — A hash function works quickly and can handle all kinds of data without errors. This ensures it delivers results efficiently without wasting time or producing useless outputs.

Testing it out yourself

Alright! It's time to see all of this in action.

Head over to browserling, where you will see a hash generator that takes in an input and provides hash values based on different algorithms. Notice how even a small change, like capitalizing a single letter, completely alters the resulting hash value.

Conclusion

So there you have it guys! Hashing isn’t just a techy term; it’s a crucial concept for ensuring the security of data, especially in systems like the Blockchain. Just like a fingerprint uniquely identifies a person, a hash value uniquely identifies data.

Now, for that fun fact I promised you — Did you know that your passwords for online accounts are typically stored as hashes? This ensures that they can’t be viewed even if the database is hacked. When you log in, the system hashes your password and compares it to the stored hash. If they match, you gain access!

While we've covered the basics here, there's a lot more to explore. If you're curious to dive deeper into hashing and its applications, feel free to consult other resources for a more in-depth understanding. Stay curious and keep learning!