Hello, in this lesson we are going to cover what a Merkle tree is. I mentioned in a previous video when we was talking about the structure of a block in blockchain, the Merkle trees are very important, and they relate to hash algorithms. So if you're not quite sure what hashing is, then feel free to check out the lesson on what is a hash, then come back to this video and we'll talk about how Merkle trees really do help the validity the validity of transactions in a block within blockchain. So what is a Merkle tree, a Merkle tree essentially takes a bunch of input, and it helps confirm its validity. So imagine if I have in the case of Bitcoin, for example, blockchain really, I have four transactions. The average block in Bitcoin has over two and a half thousand.

So obviously, this is a simplification, but once you understand the concept with four to eight or however many, the concept is just the same. And we're going to call this T one, T two, t three, and T four. So these are four individual transactions. And they obviously have their own information, their own unique ideas, all of that cool stuff. And what happens is, each one of these is fed through a hashing algorithm. The exact hashing algorithm isn't important in understanding the concept of Merkle trees.

It's always the same hashing algorithm for all of these. So this is a hashing algo rhythm and from there what we get going the wrong place then what we get is the transaction hash for the transaction hash as we discuss in the hashing video is different to the original transaction a lot of the time is a lot shorter than the original value where we will file it is. So, these are the hash values I'm just going to call it like ht one of them like from for phone the HTC One ht to h T free ht four And now these are combined into pairs. So what you get now is these are combined together. And the combination of these offered through the hashing. Sorry about that, that was in a very good line for the hashing algorithm again, so hashing Oh, let me just undo that.

I'll go River. And what I'm gonna do is just remove some of this, just have some more information, I mean for more space to deal with. So the hashing algorithm so these two Combined, they form a single piece of information. So they're essentially stuck together. By combining them, we put them through the hashing algorithm, and then we get we get a combination hash does the hash of hashes. So we're going to do is right here.

Here, we get a hash of the original transaction. And then here, we get a hash of hashes. For this is a hash of the hash if, and I'm gonna call this so new hash for example. Now I'm gonna call it h h. One. H, H And then then we get rid of this as well. Then we get rid of the title and then this is again combined.

So this is combined. And the combination is fed into the hashing algorithm again so hashing out go rhythm and from this, we get the ultimate piece of information, we get a single hash. So, and this is called the root hash the root hash So in the cordless, or Ah, and this root hash is the eventual hash of going through the Merkel tree with all of the transactions, whether you have four transactions, you have a million transaction yet 2000 however many you have to the Marya matter, you ultimately get to a root root hash and that's the whole point of the Merkle trees gaining root hash. So what this allows is, it helps prevent tamper within the transactions. Because if, let's say one of these transactions was modified, so let's say we were to, let's say we were to hack and we modified transaction one, even one little change and even if we were to change this one bit of data, this would obviously be different now and as a result, the combination of me to the different color of this would be different, which would lead to the hash of hashes being different and then ultimately, this combination will be different.

And then eventually he has a massive cascade effect and then the root hash is different as well. So this allows people to see if the block is valid. So, that is one of the amazing things about Merkle trees. Merkle trees allow the check in of the validity, validity of a bunch of transactions what is data in general so this is a very key part of blockchain and Bitcoin. There's not much to it. Other than that if you have any questions, feel free to ask.

There's something that you didn't quite understand and feel free to go over the video again, feel so unsure by hashing. Like I said, just go and check out the water they hash video. And as usual, thanks for watching and I will see you in the next lesson.