Encrypted Security Camera

A privacy-focused security camera application that runs natively on macOS (and can be ported to Linux/Raspberry Pi). It captures video from your webcam, splits it into fixed-length chunks, encrypts each chunk using AES-256-GCM, and saves it to disk. No plaintext video is ever stored.

Features

• AES-256-GCM Encryption: Provides both confidentiality and authenticity. Video chunks cannot be read or tampered with without the key.
• Chunk-Based Storage: Video is saved in 10-second encrypted chunks (.enc), enabling easy partial decryption.
• Motion Detection: Uses OpenCV background subtraction to only record when movement is detected, saving storage space.
• Raw H.264 Video: Uses ffmpeg to pipe raw frames directly into an H.264 stream, allowing seamless merging of multiple video chunks.

Prerequisites

• macOS (Intel or Apple Silicon)
• Python 3.9+
• ffmpeg installed via Homebrew

Setup Instructions

1. Install ffmpeg:

   brew install ffmpeg

2. Clone the repository and enter the directory:

   git clone https://github.com/flames778/Encrypted-Security-Camera.git
   cd Encrypted-Security-Camera

3. Set up a virtual environment and install dependencies:

   python3 -m venv venv
   source venv/bin/activate
   pip install opencv-python cryptography numpy

Usage

1. Start Recording

Run the main script to start the security camera:

python main.py

• On the first run, a new AES-256 key will be generated and saved to keys/video_key.bin. Keep this safe!
• The camera will watch for motion. When motion is detected, it will start recording and saving .enc files in the footage/ directory.
• Press Ctrl+C to stop.

2. Decrypt a Single Chunk

You can decrypt a specific .enc file back to .h264 using the decrypt tool:

python decrypt.py footage/<timestamp>.enc out.h264

You can then play the video using ffplay:

ffplay out.h264

3. Decrypt and Merge All Chunks

To decrypt all chunks in the footage/ directory and merge them into a single continuous video:

python batch_decrypt.py merged.h264

You can then play the combined video using ffplay:

ffplay merged.h264

(Alternatively, you can drag and drop merged.h264 into VLC Media Player or another supported video player).

Security Notes

• Key Management: The encryption key (keys/video_key.bin) is stored locally. If this key is lost, all recorded footage becomes permanently unrecoverable.
• Authentication: AES-GCM guarantees both the secrecy and the integrity of the footage. Any modification to a .enc file will cause the authentication tag check to fail during decryption.
• Git Ignore: The keys/ and footage/ directories are explicitly ignored by .gitignore to prevent accidentally uploading your key or encrypted videos.

Future Improvements

• Encrypted Live Streaming: Build a small HTTPS server to stream .enc chunks to a browser, which decrypts them on-the-fly using WebCrypto.
• Key on USB: Store the key on a physical USB drive. The camera will only record/decrypt if the specific USB drive is mounted.
• Cloud Auto-Upload: Safely upload encrypted chunks to a cloud provider like S3 or Google Drive. Since they are encrypted, the cloud provider cannot view the footage.
• Raspberry Pi Deployment: Swap the OpenCV webcam capture with the Pi Camera module.