SecureMQTT-ASCON

A Python-based project that demonstrates end-to-end secure data transfer over MQTT using the ASCON lightweight encryption algorithm.
It simulates multiple ESP32-like nodes (clients) that publish encrypted health sensor data (heart rate & SpO2) to a Mosquitto MQTT broker.
A server (subscriber) then receives and decrypts the data back to its original form.

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✨ Features

• Secure communication with ASCON-128 authenticated encryption
• MQTT-based publish/subscribe with paho-mqtt
• Simulation of multiple ESP32 nodes (default: 50 nodes)
• Encrypted JSON payloads containing health data
• Decryption and validation on the subscriber side
• Fully written in Python for easy testing and demonstration

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📂 Project Structure

• mqtt-ascon/
  • client/
    • client.py # Simulates multiple ESP32 nodes (publish encrypted data)
  • server/
    • server.py # Subscribes and decrypts data
• requirements.txt # Dependencies
• README.md # Project documentation

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🔧 Installation

1. Clone the repository:

   git clone https://github.com/YOUR_USERNAME/SecureMQTT-ASCON.git
   cd SecureMQTT-ASCON

2. Install dependencies:

   pip install -r requirements.txt

▶️ Usage

1. Run the Subscriber (Server)

   python server.py

   Output example:

   🖥️ MQTT Subscriber (Server) started... Waiting for messages.
   ✅ Connected to MQTT broker.
   📡 Subscribed to topic: spo2/health
   🔓 Decrypted data received at 12:10:03: {'id': '...', 'heart_rate': 72.4, 'spo2': 98.6, 'publish_timestamp': 1692341234567}

2. Run the Publisher (Clients)

   python client.py

   Output example:

   Publisher started. Press Ctrl+C to stop.
   [Node 1] Published encrypted data: {...}
   [Node 2] Published encrypted data: {...}

🔒 Encryption Details

• Algorithm: ASCON-128 (NIST Lightweight Cryptography Standard, 2023)

• Key: 16 bytes (128-bit)

• Nonce: 16 bytes (12-byte base + 4-byte counter)

• Associated Data: b"health_data"

• Payload: JSON (id, heart rate, SpO2, timestamp)

📦 Dependencies

• paho-mqtt → MQTT client library

• ascon → ASCON lightweight encryption package

Install via: bash pip install paho-mqtt ascon

📄 License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.