I built Medusa - A lossless password-based file encryption tool

#security #devtools #showdev

Medusa is an open source, client-side file encryption tool, with lossless decryption.

It allows you to encrypt any file into a .medusa file using a password, share the file and decrypt with the password.

No servers. No cloud. No accounts.

Disclaimer: This tool is provided "as is". The author is not liable for data loss. Test decryption before deleting originals.

Features

Lossless: Original filename and mime type are preserved.
Portable: .medusa files are self-describing and can be shared.
Client-Side Only: 100% browser. Your password never leaves your device.
XOR Core: Fast symmetric XOR encryption. v1. Later versions will have more industry-grade techniques.
Zero Dependencies: Vanilla JS + Web APIs only

Security Model

v1 Uses XOR

Medusa v1 uses a XOR encryption technique.
This provides casual privacy and obfuscation. It is not resistant to known-plaintext or frequency attacks.
Do not use for classified, financial, or other high-sensitivity data.
The goal of v1 is speed, simplicity, and a stable file format. Future versions will be drop-in compatible via the header version field.
Use at your own risk. Keep backups.

Quick Start

Web App

Open index.html in Chrome, Firefox, or Edge
Drop file → Enter password → Save file.ext.medusa
Drop .medusa → Enter password → Get original file back

Wrong password = corrupted output. There is no password hint or recovery.

Development

git clone https://github.com/yourname/medusa
cd medusa

Open index.html. No build, no install.

Project Structure

├── index.html
├── src/
    ├── style.css
    ├── main.js
    ├── lib/
        └── #lib functions 
└── public/
    └── medusa.png

Contributing

PRs welcome for: UI, performance, tests, CLI port.

For crypto changes, open an issue first. v1 stays XOR.

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