Given the growing reliance on cyber infrastructure and the interconnection of global industries, the Industrial Internet of Things (IIoT) is expanding into an increasing number of industries- linking the manufacturing, trade, solution development and finance application spaces. The number of IIoT devices expected to exceed millions, it is important to ensure the appropriate security solutions are implemented to prevent wide-spread security breaches. Traditional mechanisms of cyber security have been previously found to be inadequate for IIoT solutions owing to the resource-constrained nature of the devices- limited processing and energy resources, real time deadlines, size restrictions and the open, easily accessible nature of network deployments. Additionally, by joining the operational and cyber spaces, previously silo’d physical infrastructure is exposed to a greater attack space. This increases the attack space of IIoT deployments and introduces new security vulnerabilities unique to the physical operational space. Currently, there are many different opinions and specifications for what entails the IIoT and its security requirements. This work studies current IIoT specifications and presents a combined security framework, comparing requirements, restrictions, vulnerabilities, and attack space considered by different specifications.

The advent of distributed ledger technologies (DLTs) provides a new opportunity for distributed and decentralised security services- such as encryption and hashing- on IIoT devices without compromising the integrity of the devices’ operation within the deployment. While DLTs have been previously focused on the financial technology (FinTech) applications, in recent years they have been identified for their potential use in industrial spaces such as energy trade and supply chain management. One industry which stands to greatly benefit from combining the interconnected and distributed nature of IIoT networks with DLTs is energy generation- especially for emerging and developing economies that are striving to ensure universal electrification. The smart transactive microgrid use case seeks to harness and combine emerging Industry 4.0 technologies, such as the IIoT and DLTs, into a smart microgrid infrastructure that allows end users to self-generate and trade electrical energy through renewable energy generation sources. The smart transactive microgrid seeks to provide control back to end users by allowing them control and independence for their energy requirements while providing a platform from which a new industry and income generation stream may provide job creation and stimulation to the GDP growth in emerging economies. This work further investigates the feasibility of using DLTs in IIoT settings. As a use case, we consider the implementation of a DLT-IIoT enabled smart transactive microgrid in the context of use in an emerging market economy. This use case incorporates several technical challenges, such as limited computational and communication resources in remote rural settings where microgrids are of greatest value to off-grid communities. A design for DLT-enabled microgrid is presented; demonstrating that the majority of prominent DLTs- such as Bitcoin, IoTA and Nano- are unsuitable for deployment in embedded computing platforms. As such, an alternative consensus mechanism for IIoT is explored; based on the proximity of the node and the event it is reporting. In taking advantage of existing IIoT operations, improvements can be made in DLT resource and processing consumption; thereby accommodating the real time deadlines and resource constraints of the microgrid and its rural deployment environment.