ICS Testbed Tetris: Practical Building Blocks Towards a Cyber Security Resource

Cyber attacks on Critical National Infrastructure (CNI) can be hugely detrimental to society, notably via compromising Industrial Control Systems (ICS) that underpin core CNI functions. In order to explore in-depth ICS Cyber Security challenges, testbeds are an essential tool, avoiding the need to experiment exclusively on live systems. However, ICS testbed creation is a complex multidisciplinary challenge, with a plethora of conflicting requirements. This paper, based on over six years of ICS testbed research and development that spans multiple diverse applications, proposes a flexible high- level model that can be adopted to support ICS testbed development. This is complemented by a baseline set of practical implementation guidance incorporating related and emerging technologies. As a collective, the model and implementation guidance offers a go-to guide for a wide range of end-users. Furthermore, it provides a coherent foundational structure to- wards establishing an online "living" resource, which can be expanded over time through broader community engagement