🗳️ BlockVote - Blockchain-Based E-Voting System

Tamper-proof voting. Powered by Blockchain.

A secure and decentralized web application that enables online voting using blockchain technology to ensure transparency, tamper-resistance, and trust. Built with a full-stack architecture using React, Node.js, MongoDB, and JWT-based authentication.

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🔐 Key Features

• Blockchain-Powered Voting: Every vote is recorded in a tamper-proof blockchain ledger.
• Secure Passwords: User passwords are hashed using bcrypt before storing in the database.
• Two Roles: Admins can create/manage sessions, voters can vote and view results.
• Session Management: Admins can create and close voting sessions, view live vote counts, and validate the blockchain.
• Real-time Results: Results are available once sessions are closed.
• Authentication & Authorization: JWT-secured login and protected routes.
• Responsive UI: Built using TailwindCSS, optimized for both desktop and mobile views.
• Session-based State: Sessions are categorized into active and completed for voters.

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🔐 Authentication & Security

• Password Hashing: All user passwords are hashed using bcrypt before being stored in MongoDB. Plain text passwords are never saved.
• JWT Authentication: On login, users receive a signed JWT token that is stored in localStorage and used to access protected routes.
• Role-Based Access Control: Admin and Voter roles are enforced both on frontend (UI) and backend (API) using middleware.
• Blockchain Integrity: Votes are written to a tamper-proof blockchain with SHA256 hashing, and admins can validate chains.

🚀 Tech Stack

Frontend	Backend	Database	Security
React	Node.js	MongoDB	JWT Auth
React Router	Express	Mongoose	Role-Based Middleware
Tailwind CSS			Blockchain Validation
			Password Hashing using bcrypt

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📦 Project Structure

EVotingSystem/ │ ├── Backend/ │ ├──config/ │ ├── models/ │ ├── routes/ │ ├── middleware/ │ ├── utils/ │ └── server.js │ ├── Frontend/ │ ├── src/ │ │ ├── api/ │ │ ├── assets/ │ │ ├── pages/ │ │ ├── components/ │ │ ├── context/ │ │ ├── utils/ │ │ ├── index.css/ │ │ └── App.jsx │ ├── .gitignore ├── README.md └── package.json

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🛠️ Setup Instructions

🔑 Prerequisites

• Node.js and npm installed
• MongoDB running locally or cloud-based (e.g. MongoDB Atlas)

🔧 Backend

1. Navigate to the backend folder:

   cd Backend

2. Create a .env file with:

   PORT=5050
   MONGO_URI=your_mongodb_connection_string
   JWT_SECRET=your_jwt_secret
   

3. Install dependencies:

   npm install
   

4. Start backend server:

   node server.js
   

Frontend

1. Navigate to the frontend folder:

   cd Frontend

2. Install dependencies:

   npm install

3. Start React frontend:

   npm run dev
   
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Skills Demonstrated

• Full-stack development with React, Node, and MongoDB
• RESTful API design and secure authentication with JWT
• Blockchain data structure for verifiable transactions
• React Router DOM navigation and conditional rendering
• Role-based route protection
• UI/UX design using TailwindCSS
• Clean code architecture with modular separation

Why is it Secure?

• Blockchain Integrity: Every vote is added as a new block linked to the previous one using SHA256 hashing. Blocks are immutable once written.
• JWT Authentication: Prevents unauthorized access to admin or voter routes.
• Role-based Authorization: Admin-only and voter-only APIs protected by middleware.
• Tamper Detection: Admin can validate the blockchain integrity for each session.

Contact

Built by Olivia Chattopadhyay