1. TELE3119: Trusted Networks Week 10
Course Coordinator:
Prof. Aruna Seneviratne, Room EE 312 –
Course web-page:

2. IoT and Blockchains Access & Availability Confidentiality Integrity
Authentication
Cryptography
Symmetric
Asymmetric
IoT & Blockhains
Stream Ciphers
Block Ciphers
Trusted Networks

3. IoT/Blockchains
Blockchain will enable IoT ecosystems to break from the traditional broker-based networking paradigm, where devices rely on a central cloud server to identify and authenticate individual devices.”
“Blockchain technology will enable the creation of secure mesh networks, where IoT devices will interconnect in a reliable way while avoiding threats such as device spoofing and impersonation.”
“With every legitimate node being registered on the blockchain, devices will easily be able to identify and authenticate each other without the need for central brokers or certification authorities, and the network will be scalable to support billions of devices without the need for additional resources.
Security
8-3

4. Advantages
Trusted Networks

5. Decentralised Architecture
 Manufacturer
The current centralized model has a high maintenance cost
Consumer,
lack of trust in devices that ``phone home'' in the background
need for a ``security through transparency’’
Consider the distribution of software updates to millions of devices for years after they have been long discontinued
One of major security issues
Solution:  a scalable, trustless peer-to-peer system that can operate transparently and distribute data securely
Blockchains provide an elegant solution
Security
8-5

6. Example
 All the IoT devices of a manufacturer operate on the same blockchain network.
The manufacturer deploys a smart contract that allows them to store the hash of the latest firmware update on the network.
The devices either ship with the smart contract's address baked into their blockchain client, or they find out about it via a discovery service
They can then query the contract and find out about the new firmware and request it by its hash via a distributed peer-to-peer filesystem
 The first requests for the file will be served by the manufacturer’s own node (also taking part into the network)  
After the binary has propagated to enough nodes the manufacturer's node can stop serving it!
 Assuming the devices are configured so as to share the binary they got  a device that joins the network long after the manufacturer has stopped participating in it, can still retrieve the sought after firmware update and be assured that it is the right file
Device polls the manufacturer's server for an update and gets a 404 error
Security
8-6

7. Case Studies
Security
8-7