1.1 - Orientation Web3 Assignment.md

1.1 - Orientation (Web3)

Assignment Link

Another Link

Or

---

Intro to Proof of Work

Assignment #1

What if I ask you the following question — Give me an input string that outputs a SHA-256 hash that starts with 00000 . How will you do it?

A: You will have to brute force until you find a value that starts with 00000

Node.js code

const crypto = require("crypto");

// Function to find an input string that produces a hash starting with '00000'
function findHashWithPrefix(prefix) {
  let input = 0;
  while (true) {
    let inputStr = input.toString();
    let hash = crypto.createHash("sha256").update(inputStr).digest("hex");
    if (hash.startsWith(prefix)) {
      return { input: inputStr, hash: hash };
    }
    input++;
  }
}

// Find and print the input string and hash
const result = findHashWithPrefix("00000");
console.log(`Input: ${result.input}`);
console.log(`Hash: ${result.hash}`);

Assignment #2

What if I ask you that the input string should start with 100xdevs ? How would the code change?

Node.js code

const crypto = require("crypto");

// Function to find an input string that produces a hash starting with '00000'
function findHashWithPrefix(prefix) {
  let input = 0;
  while (true) {
    let inputStr = "100xdevs" + input.toString();
    let hash = crypto.createHash("sha256").update(inputStr).digest("hex");
    if (hash.startsWith(prefix)) {
      return { input: inputStr, hash: hash };
    }
    input++;
  }
}

// Find and print the input string and hash
const result = findHashWithPrefix("00000");
console.log(`Input: ${result.input}`);
console.log(`Hash: ${result.hash}`);

Assignment #3

What if I ask you to find a nonce for the following input -

harkirat => Raman | Rs 100
Ram => Ankit | Rs 10

Node.js code

const crypto = require("crypto");

// Function to find an input string that produces a hash starting with '00000'
function findHashWithPrefix(prefix) {
  let input = 0;
  while (true) {
    let inputStr =
      `
harkirat => Raman | Rs 100
Ram => Ankit | Rs 10
` + input.toString();
    let hash = crypto.createHash("sha256").update(inputStr).digest("hex");
    if (hash.startsWith(prefix)) {
      return { input: inputStr, hash: hash };
    }
    input++;
  }
}

// Find and print the input string and hash
const result = findHashWithPrefix("00000");
console.log(`Input: ${result.input}`);
console.log(`Hash: ${result.hash}`);

Assignment #4

Let's Explore Anders Brownworth's Blockchain Demo.

---

For more details, visit the Notion page.

Another Link 100xdevs.