Introduction:

“Things” getting connected to the Internet and getting “Smart”

What is needed for IoT?:

• “Smart” devices
• Communication
• Applications

Why connect things to the internet?

• IoT devices have power and CPU constraints
• Offloading of complicated tasks from IoT devices allows smaller and more energy efficient devices
• Host ‘Smart’ part of ‘Dumb’ devices
• Cloud applications can be updated at will of vendor
• No user interaction needed for updates

Simplified Setup for IoT: Let all devices connect to the cloud with known endpoints controlled by the vendor

• Can be scaled and is under full control of the vendor
• Home network is unknown
• No direct access to devices, but they can connect to the outside
• No problem with dead or broken devices. No need to store state at vendor

What is a Message Broker?

A pattern in software architecture In out context:

• Reachable by all devices
• Receiving messages
• Keeping state
• Forwarding messages Is just an intermediary that forwards messages between different components of the IoT

MQTT - Message Queuing Telemetry Transport

• Core is the Message Broker
• Clients can subscribe to topics
• Clients can publish data for a topic/topics
• Clients interact only with the message broker
• Uses TCP usually a long-standing connection

Subscribing to topics:

• Topics are organised in hierarchy.
• Have naming similar to the file path.
• There are two wildcards:
  1. + - place holder matching single value Ex: +/sw0 matches /switches/sw0
  2. # - place holder matching one or multiple values Ex: #/sw0 matches /switches/in/.../sw0

Security

Limited CPU resources is a major constraint while implementing security in IoT

• Confidentiality
  • Data should be transferred encrypted
  • Data processing in cloud -> cloud should be secure
• Integrity
• Availability
  • All cloud solutions rely on the internet
  • vendor cloud needs to be available too
• Safety (for IoT):
  • Depending on the devices serious injury on death are possible
  • Simple errors can get extremely expensive
  • Hardware based safety
• Privacy (for IoT):
  • Data from IoT can provide deep insights