Cryptographic Website

Overview

The basis of this project is a project as part of the Alchemy University course on blockchain and ethereum development; a course I would certainly recommend to anyone interested in getting to grips with this technology as it starts from very first principles!

The aim of the project was to build a simple website that kept track of user accounts and allowed them to securely send transactions to other acounts.

How it Works

This project uses React using Vite for the front end. I used Express.js and Node.js for the backend.

The project uses the "ethereum-cryptography" npm package to generate public and private keys. It also provides functions for hashing and converting utf-8 to bytes.

The project solves the issue of 'double-spending', where correctly signed messages can be resent to re-trigger valid transactions, by making a time-stamp mandatory in all transactions. This timestamp is then stored internally on the server. It then rejects any messages that have a timestamp that has already been used along with the message hash. Any change to the timestamp would need a different message hash.

This is not dissimilar to the idea of nonces that blockchain technologies like Ethereum and Bitcoin use.