What is a Merkle Tree?

The Merkle tree is a data structure that is used in the blockchain to verify the integrity of data. It is a tree structure, where each node contains the hash value of its child node. The root node of the tree contains the hash - the value of all data in the  block.

How does the Merkle tree work on the blockchain?

Imagine that we have a block with data about several transactions. We can create a tree where each transaction will be represented as a leaf, and their hashes will be nodes at higher levels of the tree. The root node will contain the hash - the value of the entire block.

Now, if someone tries to change data in one of the transactions, it will affect the hash values of all nodes associated with this transaction. This, in turn, will change the root hash code of the block, which will be detected during data integrity checks.

Thus, it allows you to quickly and efficiently verify the integrity of data in the blockchain.

Example of using the Merkle Tree

Let's say we have a blockchain with 10 transactions. We create a tree as follows:

• Each transaction has its own unique hash code.
• Transaction hash codes become nodes at the first level of the tree.
• Then we combine the first-level hash codes into a single hash code and get a second-level node.
• We repeat this process until we get the root node that contains the hash code of the entire block.

If someone tries to change one of the transactions in this block, it will change the hash codes of all nodes, starting with the modified transaction and ending with the root node. This will be detected the next time you try to verify the integrity of the data.

This is just a basic example of using. In real-world systems, it can be much more complex and include many additional functions to ensure data security.