1. Purdue University Fort Wayne
A Secure and Reliable Smart Home
Guoping Wang
Department of ECE
Purdue University Fort Wayne

2. Presentation Outline:
Project Objective
Introduction to IoT
Project Requirements
Contraints
Components for the project
Secure Features
Summary
Future Research

3. Project objective:
The goal of the project was to create a Secure and Reliable IoT Smart House that can monitor specific criteria, as well as control specific devices. The user will be notified of specified changes in the monitored data.
Arif

4. Internet of Things:
The Internet of Things (IoT) is the inter-networking of physical devices, vehicles (also referred to as "connected devices" and "smart devices"), buildings, and other items—embedded with electronics, software, sensors, actuators, and network connectivity that enable these objects to collect and exchange data. IoT allows objects to be controlled and gather information remotely across the already established network.
Arif

5. Project Requirements:
A Smart Home with the capability of monitoring the state of the house
Users should be able to easily make use of the Smart Home through a web application
The ability to notify the user of changes in the house state
The ability to control devices within the Smart Home from the web
Data sent to and from the Smart Home should be secure
Austin

6. Constraints Implemented Smart Devices: Humidity Sensor
Temperature Sensor
Motion Detector
Light Control
System Backups:
Battery Power

7. Component Definition Hardware Server Web Application
Raspberry Pi Model B
Control and monitor each sensor independently
Send data to server for user access
Mosquitto (MQTT)
Ensure secure and accurate data transmission
Fast and efficient message format
HTML/Javascript
MQTT libraries available for efficient programing
Enables user to access real time information
Arif

8. System Boundary

9. Interface Requirements
Government Regulations
FCC regulations to be followed
Internet
Ensure secure and reliable data transmission
Power Grid
Provide battery backup to limit down time
Sensor Interface
System that allows sensors to work together
Austin

10. Design Verification and Validation
Initial testing hardware - Raspberry Pi, Cloud MQTT, web client sample
Goal is to establish a system where each component is controlled by the web client
Successfully able to turn devices on and off with the appropriate commands
Validation of design required us to prove that the system is able to adapt to technological change
Austin

11. Top Level Functional Requirements
Create an IOT Smart Home
Interconnected system of devices
System that can measure and control sensors
Raspberry Pi with sensors
Allow communication between devices and users
MQTT server
Enable user to access current data
Web application
Arif

12. Raspberry Pi Allows multiple programs to be run at once
Simple implementation of even large systems
Many GPIO connection pins

13. Mosquitto Open Source, Free Great degree of control
Efficient message format
Austin

14. Web application HTML/Javascript Libraries available for MQTT protocol
Very easy to edit using notepad or notepad++
Universal, runs on most web browsers
regardless of OS
Small filesize
Arif

15. Planned Build
Components connected together in an Internet of Things network:
Sensors measure data to send to server
Server controls flow of data between devices
Web application connected to server to receive data and allow device control
Austin

16. Final Build
Raspberry Pi, breadboard, and devices all within a single container
Server implemented in separate Raspberry Pi
Web client local to user, communicates with server through web

17. Device Hub Casing Wood casing to contain and protect devices
Apertures for motion sensor and camera
Wall power routed in through back
Water sensor routed through top
Sound sensor, RF transmitter, and power relay are internal
Latch and hinged top for device access

18. IoT System Diagram MCU Platform: Devices within the Smart Home
MiddleWare: MQTT Mosquitto server
User App: HTML web interface
Austin

19. Test Execution Software: Hardware: Test latency of device control
Test and adjust volume of data
Test user verification system
Test system under high load
Hardware:
Test accuracy of sensors
Test camera quality
Test RF transmission
Test power loss detection and battery backup
Austin

20. Verification Results
Water detection, RF transmission, power control, and camera worked completely to specification
Motion sensor and sound sensor encountered various issues in sensitivity throughout testing
Images and videos were perfectly sent with a time delay but had to be compressed below 2 MB
Arif

21. Secure Features:
Firewall: The Raspberry Pi runs in Linux-based Raspbian Operating System. The firewall feature is activated which blocks certain kinds of network traffic, forming a barrier between a trusted and an untrusted network. For our application, only Ports 8883 and 8884 are enabled for the communication. The port 8883 is for encrypted MQTT and 8884 is for MQTT encrypted with client certification required. Only certain ports are open and only certain applications are allowed. The firewall can be easily configured and turned on and off.
Arif

22. Secure Features:
Client Authentication: The MQTT broker is configured to require a valid username and password from a client before a connection is permitted. Both the Raspberry Pi and mobile APPs need to provide correct combinations of user name and password to establish a connection. The username/password combination is transmitted in clear text and is not secure without some form of transport encryption. However, this approach does provide an easy way of restricting access to a broker and is probably the most common form of identification used.
Arif

23. Secure Features:
Client Certification: For high level of security, TLS client certification is adopted in this Smart Home system. This is the most secure method of client authentication but also the most difficult to implement in a regular embedded system. Since Linux OS is used on the edge device, it is relatively easy to implement.
TLS security is a part of the TCP IP protocol and not part of MQTT, and it provides an encrypted pipeline through which MQTT message can flow. The TLS certification provides an encryption of all MQTT message instead of MQTT message payload.
Arif

24. Secure Features:
Payload Encryption: If necessary, Payload encryption can be used to encrypt/decrypt MQTT message. Payload encryption is done at the application layer and not by MQTT broker. The data is encrypted end to end and not just between the client and the broker, however, the payload encryption will add significant overhead for the communication. In our system, Payload encryption is not employed.
Arif

25. Secure Features:
Overall, by combing Linux firewall, client user name and password, TLS encryption, this Smart IoT system is secure and meet industrial standard.
Arif

26. Summary
An IoT Smart Home using off-the-shelf Raspberry Pi, with the combination of various sensors (gas, motion, sound, water, etc) and actuators (Outlet control, camera, etc) is introduced in this paper.
Data to be monitored are: temperature, humidity, movement, water, and power. An outlet, camera, and microphone can be controlled by the user from any mobile device.
The user will be notified in any change in the monitored data, if it changes beyond their given range. The device also works while power is out in the house; which means a battery back-up and Internet hot spot can be included as well.
The transmission of data is secure and reliable with firewall configuration, client authorization and certification, payload encryption, etc.
Arif

27. Future Research:
Instead of using Raspberry Pi as front-end, Ti secure embedded Launchpad will be used which is more secure. Ti Launchpad is a bare-metal EM platform which is widely used in industry.
Android and/or IoS App developed instead of using HTML/Javascript for back-end
Arif

28. Questions?