IoT Security Threats and Risk Analysis

The increasing use of Industrial IOT (IIOT) solutions has led to an equal increase in the security risks associated with the connected devices. Security requirements engineering (SRE) aims at reducing these risks by implementing security-by-design principles. To mitigate the security risks in the industrial communication networks, the standard ISA/IEC 62443-1-1 recommends the defense-in-depth design strategy for a secure segmentation of industrial assets into security zones and conduits. Security zones associated with different trust levels signal the criticality of the assets within. However, the current SRE methodologies lack any support to security zoning; thus, they are incapable to reduce the security risks, especially in relation to IIOT. To fill this gap, we develop a layered SRE methodology in line with the SABSA framework. Starting with the business view, each successive layer brings a new level of abstraction to the design and implementation of a secure network. We use STS (Socio-Technical Systems) SRE methodology for the first two layers: the business view and the architect’s view. As STS is less suitable for risk analysis, we propose Anti-STS, a new multi antiagent threat model, which characterizes the social dependency between the attacking agents in a network environment. For the third layer of the designer’s view, we propose an Answer Set Programming (ASP) tool to obtain zoning solutions underpinned by dataflow and media integrity. Our use case scenario includes an aircraft domain comprising of the system agents (applications) and an airport domain comprising of the environment agents (staff). Our layered methodology aims to group agents in security zones controlled within domains and to derive the relevant network security requirements. It also brings in the perspectives of different stakeholders, who are vital in driving business objectives forward.