Blockchain-Based Digital Identity & Voting System (Raspberry Pi 5)

Project Purpose

This project is a decentralized, blockchain-based digital identity and voting system designed to run on a Raspberry Pi 5. It features a self-hosted Ethereum node, smart contracts for digital identity and voting, and a modern, minimalist web interface. The system is ideal for small-scale elections, club/association voting, and digital identity management.

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Table of Contents

• Features
• Architecture
• Technologies
• Screenshots & Diagrams
• Getting Started
• Project Structure
• Blockchain Node Setup
• Smart Contracts
• Backend (API)
• Frontend (UI)
• Usage
• Development Notes
• License

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Features

• 🔒 Decentralized Digital Identity: Register and verify unique identities on-chain.
• 🗳️ Secure Voting: One-person, one-vote, with transparent on-chain results.
• ⚡ Runs on Raspberry Pi 5: Lightweight, energy-efficient, and portable.
• 🖥️ Modern Minimalist UI: Apple-style, responsive, and easy to use.
• 🛠️ Open Source & Customizable: All code is MIT licensed and easy to extend.
• 📊 Live Results: View real-time vote counts directly from the blockchain.

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Architecture

graph TD;
  User["User<br/>(Web Browser)"] -- API Calls --> Backend["Backend<br/>(Node.js + Express)"]
  Backend -- Web3.js --> Geth["Ethereum Node<br/>(Geth, PoA)"]
  Geth -- Smart Contract Calls --> Contracts["Smart Contracts<br/>(Solidity)"]
  Backend -- REST API --> Frontend["Frontend<br/>(React)"]

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Technologies

• Blockchain: Ethereum (Geth, Proof of Authority)
• Smart Contracts: Solidity
• Backend: Node.js, Express, Web3.js
• Frontend: React.js (Create React App)
• Dev Tools: Truffle, Homebrew (for Mac), npm

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Screenshots & Diagrams

1. Home Page

2. Register Identity

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Getting Started

1. Hardware & OS

• Raspberry Pi 5 (or Mac/Linux PC)
• Raspberry Pi OS Lite 64-bit (or compatible Linux/MacOS)

2. Install Dependencies

• Node.js (>=18)
• npm
• Geth (Go Ethereum)
• Truffle
• Git

Quick Install for MacOS:

brew tap ethereum/ethereum
brew install ethereum
brew install node
npm install -g truffle

For Raspberry Pi:

sudo apt update && sudo apt upgrade -y
sudo apt install build-essential curl git npm -y
wget https://gethstore.blob.core.windows.net/builds/geth-linux-arm64-1.15.11-xxxx.tar.gz
# (Download and extract the latest ARM64 geth release)

3. Clone the Project

git clone <repo-url> blockchain-vote-pi
cd blockchain-vote-pi

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Project Structure

blockchain-vote-pi/
│
├── contracts/              # Solidity smart contracts
│   ├── DigitalIdentity.sol
│   └── Voting.sol
│
├── migrations/             # Truffle migration scripts
│   └── 1_deploy_contracts.js
│
├── backend/                # Node.js/Express backend API
│   ├── package.json
│   └── src/
│       ├── index.js
│       ├── web3.js
│       └── contract.js
│
├── frontend/               # React frontend
│   ├── package.json
│   └── src/
│       └── App.js
│
├── genesis.json            # Blockchain genesis file
├── truffle-config.js       # Truffle config
├── docs/                   # Documentation images/screenshots
└── README.md

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Blockchain Node Setup

1. Genesis File

The genesis.json file defines a private PoA network.

2. Initialize and Start the Node

geth init genesis.json --datadir ./mychain
geth --datadir ./mychain --networkid 2025 --http --http.api personal,eth,net,web3,miner,clique --allow-insecure-unlock --mine

These commands start your own private blockchain node.

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Smart Contracts

DigitalIdentity.sol

• Users register with a name and national ID.
• Each address can register only once.

Voting.sol

• Deployed with a list of candidates.
• Each address can vote only once.
• Votes are stored transparently on-chain.

Compile & Deploy

npx truffle compile
npx truffle migrate --network development

After deployment, update contract addresses in backend/src/contract.js.

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Backend (API)

• REST API built with Express.js
• Connects to blockchain via Web3.js
• Main endpoints:
  • GET /health : API health check
  • POST /register : Register identity
  • POST /vote : Cast a vote
  • GET /results : Get voting results

Start the Backend

cd backend
npm install
node src/index.js

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Frontend (UI)

• Minimalist, Apple-style React interface
• Register identity, vote, and view results
• Communicates with backend API

Start the Frontend

cd frontend
npm install
npm start

Open your browser at http://localhost:3000

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Usage

1. Register Identity: Enter your name and national ID to register.
2. Vote: Select a candidate and cast your vote.
3. View Results: See live vote counts for each candidate.

All actions are recorded on the blockchain for transparency.

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Development Notes

• After deploying contracts, update their addresses and ABIs in backend/src/contract.js.
• The Geth node and backend must run on the same machine or be accessible via HTTP API.
• During development, frontend and backend run on separate ports; the frontend uses a proxy setting for API calls.
• The codebase uses short, readable variable names and is designed for clarity.
• PoA network and short block times are used for fast, low-resource operation on Raspberry Pi.

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License

MIT