Overview
Participating in a hands-on IoT Cyber Defense externship focused on securing real-world IoT infrastructure for a simulated 500-room smart hotel environment. The program covers threat modeling, secure pipeline design, device identity management, encryption, replay attack prevention, monitoring, and AI-based anomaly detection.
This externship simulates the responsibilities of a security engineer defending production IoT systems.
Project 1: IoT Systems & Threat Modeling ✅
Deliverable
Objective
Develop a structured threat model for a simulated smart water management system supporting a 500-room IoT-enabled hotel.
Work Completed
- Applied the CIA Triad to IoT infrastructure
- Identified six primary IoT attack vectors
- Used STRIDE methodology to systematically uncover vulnerabilities
- Documented risks across authentication, message integrity, and device trust boundaries
Key Skills
- Threat modeling
- STRIDE framework
- Risk analysis
- Security architecture evaluation
Key Takeaway
Threat modeling forces clarity. Many vulnerabilities were not obvious until system boundaries and trust relationships were explicitly mapped.
Project 2: Python for IoT Security ✅
Deliverable
Objective
Built a mock Hydroficient HYDROLOGIC water sensor to simulate realistic IoT telemetry for downstream security testing and anomaly detection.
Implementation Highlights
- Designed a
WaterSensorclass in Python - Generated ISO 8601 UTC timestamps
- Implemented sequential counters for replay attack detection
- Simulated realistic pressure and flow values
- Injected controlled anomalies:
- Leak (abnormally high flow rate)
- Blockage (pressure imbalance)
- Stuck sensor (static readings)
- Generated and exported 100 structured JSON records
Sample Output
{
"device_id": "GM-HYDROLOGIC-01",
"timestamp": "2026-02-19T03:35:05.551904+00:00",
"counter": 6,
"pressure_upstream": 81.3,
"pressure_downstream": 75.9,
"flow_rate": 99.5
}
Project 3: Building an Insecure MQTT Pipeline ✅
Deliverable
📄 Download Vulnerability Assessment of Insecure MQTT Pipeline
Objective
Construct and exploit an intentionally insecure MQTT data pipeline to understand real-world interception, tampering, and replay risks in IoT environments.
Work Completed
- Deployed a local Mosquitto MQTT broker
- Configured Python-based telemetry publisher and dashboard subscriber
- Transmitted unencrypted telemetry over default MQTT port 1883
- Intercepted live MQTT traffic using wildcard topic subscriptions (
#) - Demonstrated message injection and replay attack scenarios
Security Findings
- No TLS encryption (all data transmitted in plain text)
- No client authentication required to connect to the broker
- No topic-level authorization controls
- No message integrity verification or replay protection
Key Skills
- MQTT protocol fundamentals
- Network traffic interception
- Publish/subscribe exploitation
- IoT attack surface analysis
Key Takeaway
IoT systems are insecure by default. Without encryption, authentication, and access control, attackers can silently observe, manipulate, or disrupt operational data flows.
Project 4: Securing the Pipeline with TLS 🚧 (In Progress)
Objective
Harden the insecure MQTT pipeline by implementing encryption, authentication, and access control to meet production security standards.
Work in Progress
- Configure Mosquitto to require TLS (port 8883)
- Generate and manage server and client certificates
- Enforce authenticated client connections
- Implement topic-based access control lists (ACLs)
- Evaluate performance and operational trade-offs of encryption
Focus Areas
- Transport Layer Security (TLS) implementation
- Certificate lifecycle management
- Secure MQTT broker configuration
- Performance vs. security evaluation
Expected Outcome
Transform a vulnerable IoT communication pipeline into a secure, encrypted, and access-controlled architecture suitable for real-world deployment.
Upcoming Projects (Coming Soon)
Project 5: Device Identity & Provisioning
Implement certificate-based authentication and prevent rogue devices.
Project 6: Replay Attack Simulation & Defense
Simulate replay attacks and implement timestamp and counter-based defenses.
Project 7: Real-Time Security Dashboard
Build a live security monitoring dashboard using Streamlit.
Project 8 (Optional): AI-Powered Anomaly Detection
Apply Isolation Forest to detect spoofed readings, timing inconsistencies, and anomalous IoT behavior.
Technologies Used
- Python
- Pandas
- MQTT
- TLS
- X.509 Certificates
- Streamlit
- Isolation Forest (Machine Learning)
- STRIDE Threat Modeling
Status
Currently progressing through the program (Week 3 of 8). Ongoing updates will be added as projects are completed.