BlockShareCloud : Blockchain-Based Decentralized Cloud Storage System

This project implements a simple decentralized cloud file sharing system using Flask, IPFS, and Blockchain technology. Users can upload files, which are stored securely on IPFS with metadata recorded on a blockchain for traceability.

Setup

1. Clone the repository:

git clone https://github.com/anushreejha/BlockShareCloud
cd BlockShareCloud

2. Create a virtual environment and activate it:

python -m venv venv
source venv/bin/activate  # For macOS/Linux
# On Windows use `venv\Scripts\activate`

3. Install the dependencies:

pip install -r requirements.txt

4. Create the necessary directories:

mkdir uploads downloads

5. Ensure IPFS is running:

ipfs daemon

6. Run the application:

python app.py

7. To access the application, open your browser and go to:

http://127.0.0.1:5000/

Features

• File Upload: Users can upload files via a simple web interface, and these files are stored on IPFS.
• Blockchain Storage: Metadata such as the file name and IPFS hash is stored on a simple blockchain for traceability.
• File Download: Users can download files by providing the IPFS hash, and the file is served with its original name and extension.
• Flask Web Framework: The application is built with Flask, offering an easy-to-use structure.
• IPFS for Decentralized Storage: Files are stored in a distributed manner using IPFS.

How It Works

1. File Upload:

• When a user uploads a file, it is saved temporarily in the uploads folder.
• The file is uploaded to IPFS, and its hash is returned.
• The hash and the original file name are recorded on the blockchain.

2. Blockchain:

• A simple blockchain implementation records details about each file (IPFS hash and file name).
• The blockchain ensures the integrity and traceability of the file metadata.

3. File Download:

• The user provides the IPFS hash to download the file.
• The system fetches the file from IPFS and saves it to the downloads folder.
• The downloaded file is renamed to its original file name with the correct extension based on metadata stored in the blockchain.

Example Usage

Uploading a File:

1. Go to the web interface.
2. Upload a file through the provided form.
3. After uploading, you will receive an IPFS hash for the file.

Downloading a File:

1. Provide the IPFS hash in the download form.
2. The system retrieves the file from IPFS and serves it for download with its original name and extension.

Notes

• Make sure the IPFS daemon is running locally on port 5001 (default for IPFS).
• The blockchain is a simple in-memory structure and does not persist between server restarts.