Encrypted Calculator Browser Extension

A Chrome/Firefox browser extension that offers a full-featured scientific calculator. All computations are performed in-memory and results are encrypted using AES-GCM before being briefly displayed as an “ENCRYPTION” animation, then decrypted and shown to the user.

Chrome Webstore: https://chromewebstore.google.com/detail/encrypted-calculator/cmjikefegmcdkiicdcknjbbllnbdjpig

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Features

• Standard arithmetic: +, -, *, /, decimal points
• Scientific functions:
  • Square root (²√)
  • Nth root (ⁿ√)
  • Square (x²) and arbitrary power (xⁿ)
  • Logarithm (log) and exponential (eˣ)
  • Factorial (x!)
  • Trigonometric: sin, cos, tan
  • Constant π
• Clear (C) and backspace (⌫) controls
• Keyboard support for numbers, operators, parentheses, Enter (evaluate), Backspace/Delete/C (clear)
• AES-GCM encryption/decryption of results using the Web Crypto API
• Cross-browser support via manifest v2 (Chrome & Firefox/Gecko)

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Installation

Chrome

1. Clone or download this repository.
2. Open chrome://extensions/ in your browser.
3. Enable Developer mode.
4. Click Load unpacked and select the project directory containing manifest.json.

Firefox

1. Clone or download this repository.
2. Open about:debugging#/runtime/this-firefox.
3. Click Load Temporary Add-on… and select manifest.json.

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Usage

1. Click the calculator icon in your toolbar to open the popup.
2. Enter or click buttons to build an expression.
3. Press = or Enter to evaluate.
   • The display will read ** ENCRYPTION ** for a moment.
   • Then the decrypted result will appear.
4. Use C to clear the entire expression or ⌫ to delete the last character.

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File Structure

/
├─ manifest.json          # Extension metadata
├─ popup.html             # Calculator UI
├─ styles/
│  └─ styles.css          # Layout & styling
└─ scripts/
   ├─ math.js             # math.js library for expression evaluation
   ├─ popup.js            # UI logic & crypto routines
   └─ background.js       # (Reserved) background event handlers

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Encryption Details

• AES-GCM with 256-bit keys
• A new random IV (12 bytes) is generated per result
• Results are first encrypted, briefly replaced by an “** ENCRYPTION **” animation, then decrypted and displayed
• Keys are generated once per browser session and stored in memory

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Contributing

1. Fork the repository.
2. Create a feature branch (git checkout -b feature/new-feature).
3. Commit your changes (git commit -am 'Add new feature').
4. Push to the branch (git push origin feature/new-feature).
5. Open a pull request.

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License

MIT License