This project was offered by Association for Computing Activities (ACA), IIT Kanpur to first-year UG students.
It was based on finding the nonce for a given string. We had to write a program that takes some data as string input. Then it tries to find a positive number x such that when x is appended to the end of the string, the SHA256 hash of this new string is less than the target, which is
0x0000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF.
The code logs the required nonce and the final hash of the string for you!
The related theory.
It was based on verifying signatures. We had to verify if the public key can decrypt the encrypted text, and that the decrypted text was equal to the unencrypted text provided by the user.
- Assignment 2(Key pair generation).js generates the Public and Private keys.
- Assignment 2(Signing).js signs a given message with the Private key.
- Assignment 2(Verification).js checks if a given encrypted message decrypted using the Public Key matches with the original message (before signing).
Assignment 3.js file takes inputs to create a .dat file containing the hash of the Transaction data.
Given the index of the block, the hash of the parent block, the target value and a binary file which contains the block body, Assignment5.js calculates the block header for this block and finds a suitable nonce value.
Aim was to create a simple web server listening on port 8787 with an endpoint which calculates the SHA-256 hash of the given string, converts it to hexadecimal representation, and returns it as JSON encoded data. Assignment6.js contains the relevant code.