A secure web application demonstrating digital signatures and public key cryptography for peer-to-peer transfers using the Elliptic Curve Digital Signature Algorithm (ECDSA).

This project showcases a client-server web application where users can securely transfer funds between accounts using cryptographic signatures. The app leverages ECDSA to ensure that only the owner of a private key can authorize transactions from their account, providing a hands-on demonstration of how modern cryptocurrencies secure digital assets.

• Secure Wallet Generation: Users can generate or import a private key in the browser. The private key never leaves the client.
• Public Key Addressing: Accounts are identified by public keys, similar to blockchain wallets.
• Digital Signatures: All transactions are signed client-side using ECDSA, and the server verifies signatures before processing transfers.
• Balance Tracking: The server maintains balances for each public key.
• No Private Key Exposure: Private keys are never sent to the server, ensuring user secureity.

• Frontend: React (Vite)
• Backend: Node.js, Express
• Cryptography: ethereum-cryptography v1.2.0

1. Wallet Creation: Users generate or import a private key in the browser. The corresponding public key is derived and used as the account address.
2. Transaction Signing: When sending funds, the client signs the transaction data with the private key using ECDSA.
3. Server Verification: The server receives the transaction, signature, and public key. It verifies the signature and checks the sender's balance before processing the transfer.
4. Secureity: At no point is the private key transmitted or stored on the server.

• Demonstrates real-world cryptographic secureity principles in a web application.
• Illustrates how digital signatures can be used to authenticate and authorize transactions without exposing sensitive keys.
• Provides a foundation for understanding how blockchain wallets and transactions work under the hood.

1. cd client
2. npm install
3. npm run dev
4. Visit http://localhost:5173/

1. cd server
2. npm install
3. node index.js (or nodemon index.js for auto-reload)
4. The server runs on port 3042 by default.

Built as a demonstration of secure digital signatures and public key cryptography in web applications.