Cryptography-Based Digital Wallet for Secure Transactions and Blockchain Integration

Abstract

As more and more people use digital finance, it has become clear that transactions need to be handled via safe, decentralised, and open platforms. This project is a digital wallet that uses cryptography and blockchain technology. The backend is built with Flask, the frontend is built with HTML/CSS, and the data is handled with JSON. The goal is to show how to use the basic ideas of cryptography and distributed ledger technology to make a safe place to do business. SHA-256 is a secure hash method that encrypts transaction data in a way that can't be reversed. Proof-of-Work (PoW) is a consensus mechanism that checks and adds new blocks to the blockchain. These two things make sure that the data is correct and authentic. Each transaction is checked, mined, and saved in a block. This block is then cryptographically connected to the previous block, making a chain that can't be changed. Some important functions are processing user transactions, mining blocks, validating the blockchain in real time, and stopping double-spending. Users can create identities, start transactions, and simulate mining processes through the wallet interface, all while using a safe and open blockchain network. This project shows how decentralised systems work by mixing blockchain physics with a real-world, web-based application. It also shows how important they are for the future of digital security and financial infrastructure.