The Merkle Tree of Cryptography and Blockchain Technology

It is necessary to have an understanding of the fundamental concepts upon which the blockchain technology is based in order to have an understanding of the blockchain itself. The Merkle tree or the so-called hash tree is probably the most notable aspect of this feature. He is responsible for the blockchain’s ability to simultaneously function in an efficient and transparent manner. In 1979, Professor Ralph Merkle was the one who received a patent for the tree concept. It is now helpful in finding solutions to problems in large decentralized networks.

What is the Merkle Tree?

A Merkle tree is a complete data structure that takes the form of a tree. The leaf vertices of a Merkle tree contain hashes derived from the data blocks that make up the tree, and the inner vertices of the tree contain hashes derived from the process of adding values to the child vertices. It establishes a connection between all of the information-bearing components among themselves.

Hash trees, also known as Merkle trees, are trees that are used to store hash values. Merkle trees are also commonly referred to as Hash Trees. The hash values of individual data blocks make up the Merkle tree’s individual leaves (such as files or collections of files). A non-leaf node is represented by a hash that is a concatenation of the strings that represent its child nodes.

The function known as hashing converts data of arbitrary length to data of a predetermined length. For instance, the simplest method to check the integrity of data is to perform a hash operation on all of the data to obtain a hash value of a fixed length, and then to publish the hash value that was generated as a result of the operation on the internet, so that the data can be hashed once more after the user has downloaded it. The outcome of the comparison operation is compared with the value of the Hash function that is available on the internet. If the two hash values are the same, it indicates that the data that was downloaded was not tampered with in any way.

Because even a slight alteration in the input will render the result of the hash operation completely unrecognizable, this is something that can be done despite the fact that it is difficult to change the characteristics of the original input based on the hash value.

Merkle Tree and Bitcoin

Hashed and represented as transaction identifiers, the strings of hexadecimal numbers that make up a Bitcoin block’s transactions are all formatted in hexadecimal (txid). Hash values are calculated for each of the transaction ids contained in a block until a single block hash value is obtained.

During the process, the Merkle tree is constructed as follows: first, the txid (Transaction ID) themselves, also known as the transaction hashes, are calculated; then, the hashes are calculated based on the sum of the transaction hashes. The Merkle tree is a binary tree, which means that the number of tree elements must always be even before moving on to the next hashing step.

If there are an odd number of transactions in the block, the hash of the final transaction is duplicated and added to itself; new hashes are calculated from the hashes of the sum of the hashes of the individual transactions. And so on, right up until a single hash, also known as the merkle root, is acquired. The information can be found in the block’s header.

The process of compiling a single hash is visually represented as a tree, with the “trunk” of the tree being the starting point from which “branches” containing hashes branch off. Actually, this is where we got the name.

The Inner Workings of the Merkle Tree

The compilation of a Merkle tree can be thought of as being analogous to the process of “data folding.” Because of him, it is now possible to represent an extensive list of transactions or any other kind of assortment of information using only one line. The wonderful thing about this system is that even if we alter just one character anywhere in the list of these same transactions, it will cause the subsequent “level” of the tree to be completely different, as well as the final hash, which is the “top” of the tree, which will also be altered.

In other words, you are unable to insert another transaction into the block or modify the data of any of the transactions that are already there. As a result of this, the Merkle tree has garnered a reputation for being an effective means of recording transactions on blockchains. Merkle Proof is another principle that can be used to verify the accuracy of information; it is based on the use of hashes. Merkle Proof is an example of a cryptographic proof. It is not necessary to examine the entire data array; rather, it is sufficient to examine individual hashes in the tree. This results in a significant reduction in the amount of computing power required for the overall process.

Merkle Tree Analogues

The concept can be interpreted in more nuanced and complicated ways. For instance, Ethereum employs a Merkle prefix tree in its architecture. Every header of an Ethereum block contains three of these trees simultaneously: one for transactions, one for information about their execution, and one for their status. In contrast to a binary tree, the value of a prefix node is also determined by its connections to the other nodes in the network. Therefore, the value is dynamic rather than fixed, which means that it is subject to change without necessitating a recalculation of all of the tree’s hashes.