Simple Rust Blockchain with PoW and Merkle Trees

This repository contains two implementations of a simple blockchain system built in Rust:

1. A basic blockchain with a Proof of Work consensus algorithm.

2. An extension of the basic blockchain with the integration of Merkle Trees for transaction verification.

Introduction

Blockchain technology forms the backbone of cryptocurrencies like Bitcoin and Ethereum.

This project serves as a simple, educational representation of how blockchains function at their core,

including mechanisms like PoW (Proof of Work) and Merkle Trees.

Getting Started

Prerequisites

Have Rust, Cargo installed in your system.

Clone

git clone https://github.com/CyndieKamau/merkleTrees_Rust.git

cd merkleTrees_Rust

Running the Program

For the Basic Blockchain;

cd simple_blockchain

cargo run

Successful running should output this;

hp@Cyndie:~/Desktop/merkleTrees_Rust/simple_blockchain/src$ cargo run
    Finished dev [unoptimized + debuginfo] target(s) in 0.11s
     Running `/home/hp/Desktop/rust/mine_new_block/target/debug/mine_new_block`
Block { index: 0, timestamp: 1693305314, data: "First Block", current_hash: "000059e58710beec19937b3c462fc09af3e1ed0e949c1cebeae496ee95804b54", previous_hash: "0", nonce: 27818 }
Type 'exit' to quit
Please enter data for block number 1: 
this is the second block
Block { index: 1, timestamp: 1693305326, data: "this is the second block", current_hash: "000059cfb8730d512eb4a44c58b6fe36b9c2f57852dbfe0aa8440ff4df0fd646", previous_hash: "000059e58710beec19937b3c462fc09af3e1ed0e949c1cebeae496ee95804b54", nonce: 170784 }
Type 'exit' to quit
Please enter data for block number 2: 
exit
See yah later!

For running the Merkle Tree program;

cd blockchain_with_merkle

cargo run

Successful program looks like this;

Finished dev [unoptimized + debuginfo] target(s) in 0.54s
     Running `/home/hp/Desktop/merkleTree/blockchain_with_merkle/target/debug/blockchain_with_merkle`
Block { index: 0, timestamp: 1693314005, merkle_tree: MerkleTree { root: Some(MerkleNode { left: None, right: None, data: "5f32a9be70edf223ccdda396a87a7ce72d38e773f5c83b37605e36f0efbc8ece" }) }, current_hash: "0000569630444c7a58e7510fe8b07d594a38f3226f02286344f45df22afe2108", previous_hash: "0", nonce: 53387 }
Type 'exit' to quit.
Enter transactions separated by ',' for block number 1: 
this is my first transaction, this is my second transaction, this is my third transaction
Block { index: 1, timestamp: 1693314061, merkle_tree: MerkleTree { root: Some(MerkleNode { left: Some(MerkleNode { left: Some(MerkleNode { left: None, right: None, data: "bc4d20e6e4b23cf4abec7672e96dc6f96bb6b0fd77cd2af2d1dab3d819e5fabe" }), right: Some(MerkleNode { left: None, right: None, data: "bc4d20e6e4b23cf4abec7672e96dc6f96bb6b0fd77cd2af2d1dab3d819e5fabe" }), data: "af326c5dba7dac555c9639ff937d2efec565674a4c392507ad701f1b56f99ba3" }), right: Some(MerkleNode { left: Some(MerkleNode { left: None, right: None, data: "27280c51ab40aa63515e90cecfd17cb3e4ffae2e3ebaa748ddb2f18d37651ce3" }), right: Some(MerkleNode { left: None, right: None, data: "edbc1656f117f39929afe6b11f4529797729f4e97b7cd6330531263402a95c45" }), data: "62a93d9854c13bb0699ad2626130b3ae538ccc48856b2588e4952db76827c947" }), data: "0719abe55019631aa71bf8186ddfbd926edcb7c74c51a14572bcc0db404f6f09" }) }, current_hash: "00006f41e173b76ac793c858939d04efa9d93ba4a4d7438cab60bd15dde5417a", previous_hash: "0000569630444c7a58e7510fe8b07d594a38f3226f02286344f45df22afe2108", nonce: 59897 }
Type 'exit' to quit.
Enter transactions separated by ',' for block number 2: 
second transaction, third transaction, fourth transaction
Block { index: 2, timestamp: 1693331831, merkle_tree: MerkleTree { root: Some(MerkleNode { left: Some(MerkleNode { left: Some(MerkleNode { left: None, right: None, data: "2ae63ab0c786494e154c58d766f7478d21f305b0245d550605c0d7c3cc7c8843" }), right: Some(MerkleNode { left: None, right: None, data: "2ae63ab0c786494e154c58d766f7478d21f305b0245d550605c0d7c3cc7c8843" }), data: "172f161678e75c3c2e7fd4b77569462d2030b3d8abdab512f097c7ec53dc11d7" }), right: Some(MerkleNode { left: Some(MerkleNode { left: None, right: None, data: "bd2facd9584174b59f7c531e37275159688e5a60c02e78c5d5d4be1ed5792d96" }), right: Some(MerkleNode { left: None, right: None, data: "749effdbf496b3d4b516641cc641ff140f89593f8d3421f730633a025cbdbef9" }), data: "805d6445fd8640d3f16dc98fc655428273b8f8611a8519b71cf5c5934517b1f9" }), data: "0e62d5801c615bb8b0529ffbc998a1f1baa855ad4262068ba405565c88fbb4eb" }) }, current_hash: "00005df5681086ab69348fe3b3e0bed97421910d83375b2ea02e273659a5a01a", previous_hash: "00006f41e173b76ac793c858939d04efa9d93ba4a4d7438cab60bd15dde5417a", nonce: 165510 }

Basic Blockchain

This implementation is a straightforward representation of a blockchain system. It features:

• Block creation with index, timestamp, data, and previous hash.

• A Proof of Work consensus algorithm with a set difficulty of 4.

• SHA256 hashing for block verification.

Blockchain with Merkle Trees

Building on the basic blockchain, this version integrates Merkle Trees to handle multiple transactions in each block.

Features include:

• Block creation with multiple transactions separated by a comma ','.

• Efficient and verifiable transaction handling with Merkle Trees.

• All features from the basic blockchain.

Here's a simple illustration showing a respective Merkle tree for Block number 8;

.

Block 8;

Type 'exit' to quit.
Enter transactions separated by ',' for block number 8: 
25th tx, 26th tx, 27th tx, 28th tx
Block { index: 8, timestamp: 1693332033, merkle_tree: MerkleTree { root: Some(MerkleNode { left: Some(MerkleNode { left: Some(MerkleNode { left: None, right: None, data: "61ef6ea548ce403c478964519a8eeacdf0406f21636bb85afd58bb065df5bedd" }), right: Some(MerkleNode { left: None, right: None, data: "ccdb02374a3a4e5f0ac3bdd651876f8395f57b3935c89c9ef4ef8cc8e248eb23" }), data: "1b71f51107ff6acaabed3102f498d77655f617ad339d42b1f480306a63502e84" }), right: Some(MerkleNode { left: Some(MerkleNode { left: None, right: None, data: "c33b22765a6480104048f022be86a0d765ac86b634676272fd1cb8453f33c44b" }), right: Some(MerkleNode { left: None, right: None, data: "bc3bf4c5135ea276efe1f1474a1702a9d27e883af8f2bcf803b94975871afea3" }), data: "a36ef17b69605340139249b51f166225f3f5d9e0561e167e0a9257268c567de2" }), data: "6ca2ab3d74876dc8afa3f5e10b08805837e9d62034835697e4fe8fe89f4687be" }) }, current_hash: "0000fd017f2ef866369302f0bedce28efddf5ffb6954e6f74e93d3d532e0f4f7", previous_hash: "0000fba3713ea65377c201be8dc462f0de5924510e40c22302e212641cd32ef8", nonce: 27870 }