CipherChain - Decentralized File Sharing System

A blockchain-based decentralized file sharing system built on Aptos blockchain that allows users to securely upload, encrypt, and share files with granular access control.

Home Page	About Us Page	Contact Us Page
File Retrieval Page	Petra Wallet Connection	Request to store metadata on chain
Retrieving File	Transactions on Explorer	View Functions on Explorer
Entry Functions on Explorer	Request to register user

Project Overview

This project implements a decentralized file sharing system where users can:

• Upload files with client-side encryption
• Store files on IPFS with Pinata
• Manage file access through smart contracts
• Share files with specific users
• Download and decrypt shared files

Architecture Flow

The system follows these primary workflows:

1. File Upload Flow:

2. File Retrieval:

Technologies Used

Blockchain & Smart Contracts

• Aptos Blockchain
• Move Programming Language
• Aptos SDK

Frontend

• React.js with TypeScript
• Petra Wallet Integration
• crypto-js for encryption

Storage

• IPFS (InterPlanetary File System)
• Pinata IPFS Pinning Service

Development Tools

• Vite
• Node.js
• npm

Features

• 🔐 Client-side AES encryption
• 📁 Decentralized file storage on IPFS
• 🔗 Blockchain-based access control
• 👥 User-to-user file sharing
• 🎯 Granular access management
• 📱 Responsive web interface

Transactions

-New users will be asked to register
-When you upload a file, you'll get a signature request to safely store metadata about file on-chain

Getting Started

• Node.js (v14 or later)
• npm
• Aptos CLI
• Petra Wallet Browser Extension

Installation

1. Clone the repository

git clone https://github.com/PratyushChaudhary/dappthon.git
cd dappthon

2. Install dependencies for both contracts and frontend

# Install Move dependencies
cd contracts
aptos init

# Install frontend dependencies
cd ../frontend
npm install

3. Set up environment variables

VITE_PINATA_API_KEY =YOUR_PINATA_API_KEY
VITE_PINATA_SECRET_KEY =YOUR_PINATA_SECRET_KEY
VITE_EMAILJS_SERVICE_ID=YOUR_EMAILJS_SERVICE_ID
VITE_EMAILJS_TEMPLATE_ID=YOUR_EMAILJS_TEMPLATE_ID
VITE_EMAILJS_USER_ID=YOUR_EMAILJS_USER_ID
VITE_CONTRACT_ADDRESS=YOUR__CONTRACT_ADDRESS

Configuration

• Update addresses under Move.toml with your deployed contract address (refer to .aptos/config.yaml).
• Update the NETWORK in frontend/src/utils/constants.ts to your APTOS network (currrently set to testnet).
• Configure your environment variables
• Make sure your Petra wallet is connected to the correct network (testnet/mainnet)

4. Deploy smart contracts

cd contracts
aptos move publish

5. Start the frontend application

cd ../frontend
npm run dev

Smart Contract Structure

contracts/
├── sources/
│   ├── user.move         (User management)
│   ├── file_upload.move  (File metadata storage)
│   └── file_access.move  (Access control)

Frontend Structure

frontend/
├── src/
│   ├── components/
│   ├── contexts/
│   ├── services/
│   ├── hooks/
│   └── utils/

Usage

1. Connect Wallet

• Click "Connect Wallet" button
• Approve connection in Petra wallet

2. Upload File

• Select file
• Enter encryption password
• Click "Upload & Encrypt"
• Save the IPFS hash and password

3. Share File

• Enter recipient's address
• Confirm transaction in wallet

4. Download File

• Enter IPFS hash
• Provide decryption password
• Click "Download & Decrypt"

Extended Use Cases

Our decentralized file sharing system has numerous potential applications across various sectors:

1. Government Certificate Authentication

• Prevents certificate fraud through public verification
• Stores certificates with location and recipient data
• Enables mass verification through public ledger
• Quick fraud detection and reporting
• Creates transparent certificate ecosystem

2. Secure Cybercafe Operations

• Time-bound file sharing capabilities
• Automatic access revocation
• Mandatory directory cleanup protocols
• Prevents unauthorized data retention
• Enhanced user privacy protection

3. Healthcare Record Management

• Secure patient record sharing
• Controlled access for healthcare providers
• Complete audit trail of access
• Patient-controlled data sharing
• Compliance with healthcare regulations
• Emergency access protocols

4. Educational Institution Management

• Secure transcript and certificate distribution
• Real-time verification system
• Research paper sharing platform
• Student record management
• Cross-institution collaboration
• Alumni document access

5. Legal Document Handling

• Secure contract sharing
• Version control with timestamps
• Multi-party access control
• Compliance audit trails
• Court document management
• Client-attorney privileged sharing

6. Corporate Data Management

• Secure document sharing
• Employee record management
• Project documentation
• Board meeting materials
• Shareholder documents
• Inter-department file sharing

7. Research Collaboration

• Secure data sharing
• Version control
• Access management
• Citation tracking
• Research output protection
• Cross-institution collaboration

8. Media and Entertainment

• Digital rights management
• Content distribution
• Access control for premium content
• Proof of ownership
• Revenue sharing management

9. Real Estate

• Property documentation
• Title deed management
• Rental agreements
• Property inspection reports
• Buyer-seller document exchange

10. Supply Chain Management

• Certificate of origin
• Quality inspection documents
• Shipping documentation
• Customs clearance
• Product authenticity verification

Security Considerations

• All files are encrypted client-side before uploading
• Encryption keys never leave the user's browser
• Smart contract handles access control
• Wallet signatures required for all transactions

Acknowledgments

I would like to express my sincere gratitude to my teammate Aman Pandey for their valuable contributions to this project.