TELE3119: Trusted Networks Week 10 Course Coordinator: Prof. Aruna Seneviratne, Room EE 312 E-mail – a.seneviratne@unsw.edu.au Course web-page: https://subjects.ee.unsw.edu.au/tele3119/

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

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

Advantages Trusted Networks

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

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

Case Studies https://www.chainofthings.com/ Security 8-7