🔐 Chat Encryptor

A minimal, elegant web app to encrypt and decrypt English messages using a custom reversible cipher.

Tech

• Frontend: HTML, CSS, JavaScript (Fetch API)
• Backend: Python (Flask)
• Storage: None (stateless)

Cipher (high-level)

Encryption steps:

1. Replace vowels: a→@, e→3, i→!, o→0, u→∪ (case-insensitive)
2. Reverse every 3rd word (per line)
3. Shift code points by +3 (keeps newlines)
4. Insert a single random salt symbol between words: " space space "

Decryption reverses the above in reverse order.

Notes:

• Multiple spaces are normalized to single spaces during encryption.
• Newlines are preserved; salts are inserted only within each line.

Run locally (Windows PowerShell)

1. Create a virtual environment and install dependencies:

python -m venv .venv
.\.venv\Scripts\Activate.ps1
pip install -r requirements.txt

2. Start the Flask server:

python -m app.app

3. Open the app: http://127.0.0.1:5000/

Project Structure

• app/ – Flask app and cipher logic
  • app.py – Flask routes (UI + APIs)
  • cipher.py – Encryption/decryption logic
• templates/index.html – UI
• static/css/styles.css – Styles
• static/js/app.js – Frontend logic

API

• POST /api/encrypt – body: { "text": "..." } → { "encrypted": "..." }
• POST /api/decrypt – body: { "text": "..." } → { "decrypted": "..." }

License

MIT