OPAQY: Advanced Polymorphic Python Obfuscator

OPAQY is an advanced Python script obfuscation tool designed to protect your intellectual property (IP) and research against static analysis, reverse engineering, and automated deobfuscation. It leverages a multi-layered, polymorphic encryption scheme using the custom LeCatchu v9 (LehnCATH4) cryptographic engine.

Disclaimer: This tool is intended strictly for legitimate uses: protecting your own intellectual property, educational purposes, security research, and authorized red team/penetration testing exercises. Any malicious use is strictly prohibited and is the sole responsibility of the user.

🌟 Key Features

• Multi-Layered Encryption: Implements "indent" layers for recursive encryption, significantly increasing resistance to linear deobfuscation.
• Polymorphic Decoys: Generates multiple fake encrypted code blobs that confuse analysts and automated tools, as only one is the true payload.
• Custom Cryptography: Powered by the LeCatchu v9 (LehnCATH4) engine, a custom high-entropy stream cipher built on the BLAKE2b hash function.
• Dynamic S-Box Generation: The core cryptographic substitution box (S-Box) is dynamically generated and shuffled on every run, ensuring a unique cipher mapping each time.
• Integrity Verification: Uses a built-in TAC (Tag Authentication Code) mechanism for simple integrity checking of the encrypted data.
• Pure Python Output: The resulting obfuscated file is 100% pure Python, requiring no external dependencies or compiled binaries to run.

🚀 Installation

OPAQY is a standalone Python script. No special installation is required beyond a standard Python 3 environment.

1. Clone the repository:

   git clone https://github.com/aertsimon90/opaqy
   cd opaqy
   

2. Ensure Python 3 is installed:

   python --version
   # Expected output: Python 3.x.x
   

🛠️ Usage

OPAQY can be run in two modes: Command Line (for batch/scripting) or Interactive Menu (for quick use).

1. Command Line Mode (Recommended)

Use command-line arguments to specify input, output, and all obfuscation parameters.

python opaqy.py <input_file> <output_file> [options]

Example

This example uses recommended settings: 12 decoy copies, 1 depth layer, a 128-digit key, and only the final Base64 wrapper.

python opaqy.py my_script.py obfuscated_script.py -c 32 -d 1 -k 128 --no-per-b64 --final-b64

| Argument | Description | Default | Recommended | | :--- | :--- | :--- | :--- | | -c, --count | Number of fake/decoy code chunks. | 4 | 8 - 64 | | -d, --depth | Obfuscation depth/layers (recursive encryption). | 1 | 1 - 2 (Avoid > 2) | | -k, --keylength | Cryptographic key digit length. | 64 | 64 - 256 | | --per-b64 | Enable Base64 wrapping on intermediate layers. | True | False | | --no-per-b64 | Disable Base64 on intermediate layers. | - | - | | --final-b64 | Enable final Base64 wrapper. | True | True | | -q, --quiet | Suppress detailed output. | False | - |

---

2. Interactive Menu Mode

Run the script without arguments to start the interactive console menu.

python opaqy.py

Follow the on-screen prompts to select options and input file paths.

⚠️ Performance and Size Warning

Please be mindful of the settings, as they have a significant impact on the output file size and runtime performance:

• Depth (Layers): Depth greater than 1 will significantly slow down execution startup time, as each layer requires full decryption at runtime.
• Size Growth: Every additional layer causes exponential size growth. For example, 1-2 layers can turn a 1 KB script into 500 KB to 3 MB+.

The LeCatchu v9 Engine

OPAQY relies on the custom, in-house developed LeCatchu v9 cryptographic engine (also known as LehnCATH4).

LeCatchu v9 is a proprietary, non-standard stream cipher utilizing BLAKE2b as its core hash function to generate high-entropy, unpredictable key streams.

• Custom Key Scheduling: Keys are processed using iterative BLAKE2b hashing (process_hash and hash_stream).
• Substitution: The custom encode/decode functions implement a substitution cipher where the S-Box (self.sbox) is unique per run.
• Integrity: The add_tactag and check_tactag methods provide a simple integrity check using a Tag Authentication Code (TAC).

For more details on the LeCatchu engine, please refer to its dedicated repository:

• LeCatchu Repository: https://github.com/aertsimon90/LeCatchu

---

👨‍💻 Developer

• OPAQY Developer: Simon Scap
• Cryptographic Engine: LeCatchu v9 - LehnCATH4 (2025)

As of 2025, this is one of the most advanced open-source Python obfuscators available. Even its name ('OPAQY' → opaque = impenetrable, invisible) reveals its intent. If the user is protecting their own legitimate software → it’s an outstanding tool. If the user intends to conceal malicious code → please do not.