Building a Simple Cryptocurrency with Node.js
In this article, we’ll explore the world of blockchain and cryptocurrency development using Node.js. We’ll create a simple cryptocurrency from scratch, covering the basics of blockchain technology and Node.js development.
What is a Blockchain?
A blockchain is a digital record of transactions that is shared among nodes of a computer network. It’s an innovative, decentralized, and distributed public ledger that keeps a record of a growing list of transactions known as blocks.
Properties of a Block
Every block in the chain has the following properties:
- Proof of work: The amount of computational effort required to get a block hash
- Block hash: Block ID derived through cryptographic calculation
- Timestamp: Time when the block was created
- Index: Block’s position on the chain
- Data recorded on the blockchain
- The previous block’s hash
Creating Our First Block
To start, we need to install the JavaScript crypto-js package in our project folder. Then, we’ll create a new file called nodejsCoin.js and add the following code:
“`javascript
const SHA256 = require(‘crypto-js/sha256’);
class Block {
constructor(index, timestamp, data, previousHash) {
this.index = index;
this.timestamp = timestamp;
this.data = data;
this.previousHash = previousHash;
this.hash = this.generateHash();
}
generateHash() {
return SHA256(this.index + this.timestamp + this.data + this.previousHash).toString();
}
}
“`
Creating the Blockchain
Next, we’ll create a blockchain class that will manage the chain of blocks:
“`javascript
class Blockchain {
constructor() {
this.chain = [this.createGenesisBlock()];
}
createGenesisBlock() {
return new Block(0, ’11/04/2022′, ‘First block on the chain’, ‘0’);
}
getTheLastBlock() {
return this.chain[this.chain.length – 1];
}
addNewBlock(newBlock) {
newBlock.previousHash = this.getTheLastBlock().hash;
newBlock.hash = newBlock.generateHash();
this.chain.push(newBlock);
}
validateChainIntegrity() {
for (let i = 1; i < this.chain.length; i++) {
if (this.chain[i].hash !== this.chain[i].generateHash()) {
return false;
}
}
return true;
}
}
“`
Testing Our Blockchain
Finally, we’ll create an instance of the blockchain and test it:
“`javascript
const logCoin = new Blockchain();
logCoin.addNewBlock(new Block(1, ’11/04/2022′, { sender: ‘John’, receiver: ‘Jane’, quantity: 10 }));
logCoin.addNewBlock(new Block(2, ’11/04/2022′, { sender: ‘Jane’, receiver: ‘John’, quantity: 5 }));
console.log(JSON.stringify(logCoin, null, 5));
“`
This will output the entire blockchain in JSON format.
Conclusion
In this article, we’ve successfully built a simple cryptocurrency using Node.js. We’ve covered the basics of blockchain technology and Node.js development, and demonstrated how to create a blockchain and add new blocks to it. While our coin doesn’t meet the cryptocurrency market standard, we’ve gained a foundational knowledge of blockchain development.