ChaCha20 Video Encryption System

Overview

This project implements a real-time video encryption system using the ChaCha20 stream cipher. The system captures video from a webcam on a Raspberry Pi, encrypts each frame using ChaCha20 encryption, and transmits the encrypted data over a network to a receiving computer for decryption and display.

Project Purpose & Learning Objectives

This project demonstrates:

• Real-time cryptographic operations on video data
• Stream cipher implementation using ChaCha20
• Network programming with socket communication
• Performance optimization for real-time video processing
• Cryptographic key management and nonce generation
• Cross-platform development (Raspberry Pi to PC communication)

Technical Implementation

Architecture

• Sender (Raspberry Pi): Captures video, encrypts frames, sends over network
• Receiver (PC): Receives encrypted data, decrypts frames, displays video

Key Features

• ChaCha20 Stream Cipher: Uses 32-byte key and 16-byte nonce per frame
• Real-time Processing: Optimized for live video streaming
• Performance Monitoring: Tracks encryption/transmission times and FPS
• Frame-by-frame Encryption: Each frame uses a unique nonce for security
• Automatic File Management: Saves encrypted frames and decrypted images

Security Features

• Unique Nonce per Frame: Prevents replay attacks and ensures frame uniqueness
• Secure Key Management: 32-byte ChaCha20 key for strong encryption
• Frame Integrity: Maintains video quality while ensuring confidentiality

File Structure

chacha20-video-encryption/
├── src/
│   ├── sender.py          # Raspberry Pi video capture and encryption
│   └── receiver.py        # PC video decryption and display
├── video_link.txt         # Demonstration video links
└── README.md             # This file

Dependencies

• Python 3.8+
• Project Python packages are listed in requirements.txt:
  • opencv-python - Video capture and processing
  • cryptography - ChaCha20 encryption implementation
  • numpy - Array operations for image data

Installation & Setup

Prerequisites

Install dependencies using requirements.txt (recommended to use a virtual environment):

pip install -r requirements.txt

Configuration

1. Update IP addresses in both sender.py and receiver.py
2. Ensure both devices are on the same network
3. Configure camera settings (resolution, frame rate) as needed

Usage

Running the System

1. Start the receiver (PC):

   python src/receiver.py

2. Start the sender (Raspberry Pi):

   python src/sender.py

Controls

• 'q' key: Quit the application
• Frame limit: Set to 100 frames by default (configurable)

Performance Metrics

The system tracks and displays:

• Encryption time per frame
• Transmission time per frame
• FPS (Frames Per Second) calculation
• Total processing time for performance analysis

Demonstration

Video Demonstration

Click the image above to watch the full demonstration

The video shows:

• Real-time video encryption and decryption
• Performance metrics and system operation
• Cross-platform communication between Raspberry Pi and PC
• Live encryption/transmission timing measurements

Technical Specifications

• Encryption Algorithm: ChaCha20 stream cipher
• Key Size: 32 bytes (256 bits)
• Nonce Size: 16 bytes (128 bits)
• Video Resolution: 640x480 (configurable)
• Network Protocol: TCP socket communication
• Port: 8080 (configurable)

Security Considerations

• Forward Secrecy: Each frame uses a unique nonce
• Key Management: Secure key distribution assumed
• Network Security: Implement additional TLS/SSL for production use
• Nonce Generation: Uses cryptographically secure random generation

Future Enhancements

• Key Exchange Protocol: Implement secure key distribution
• Compression: Add video compression before encryption
• Error Handling: Improve network error recovery
• GUI Interface: Add user-friendly interface
• Multi-client Support: Support multiple receivers

Educational Value

This project serves as an excellent learning tool for:

• Understanding stream ciphers and their applications
• Real-time cryptographic system design
• Network programming and socket communication
• Performance optimization in cryptographic applications
• Cross-platform development and deployment

License

This project is part of ECE4301 coursework and is intended for educational purposes.

Video Link

https://www.youtube.com/watch?v=ZtI_uvnqqgs