Leslie Fernando prodigy_cs_02

Image Encryption & Decryption

This Python script allows users to encrypt (lock) and decrypt (unlock) images using a basic pixel-based transformation method. It shifts pixel values using a fixed secret key to obscure the original image and later restores it using the reverse operation.

Features:

• Locks (encrypts) an image using pixel value manipulation
• Unlocks (decrypts) the image back to its original form
• Simple to use from the terminal
• Keeps file format and size unchanged

How it works:

• Each pixel value (RGB) in the image is increased by a fixed SECRET_KEY value (modulo 256) during encryption.
• Decryption subtracts the same SECRET_KEY to retrieve the original image.
• Uses Python Imaging Library (PIL) and NumPy for image processing.

Sample Terminal Output:

1. Locking Example Enter original image path: sample.jpg Save encrypted image as: encrypted.jpg Image successfully locked and stored at: encrypted.jpg

2. Unlocking Example Enter encrypted image path: encrypted.jpg Save decrypted image as: unlocked.jpg Image successfully unlocked and saved at: unlocked.jpg

How to Run:

1. Save the script as image_locker.py

2. Make sure Pillow and NumPy are installed: pip install pillow numpy

3. Run the script: python image_locker.py

4. Follow the on-screen prompts to lock or unlock an image.

Note: The SECRET_KEY is fixed at 50. Changing this value without re-encrypting will not give accurate results during decryption.