Aligned with the UK Research Institute in Secure Hardware and Embedded Systems (RISE), this project seeks to identify and address the critical security issues arising from the creation of hardware platforms through the use of composable hardware systems. Predominantly, current hardware architectures are statically defined and deliver therefore a predetermined level of security and properties by which its resilience can be verified. In the simplest case, a static design supporting hardware extension, for example through a exported bus, such as PCIe, will deviate from the design's initial security principles and will require mechanisms of encapsulation in its security model to constrain the indeterminable mechanisms by which extension of a system can perturb a static security model. Although the provision of composable hardware may have understood security principles covering the creation of the resulting hardware platform, the arbitrary nature of composing the elements of a computer means that the resulting permutations lack any model of security by which threat models and mitigations can be evaluated. The project proposes to conceptualise and evaluate across the design space of composable hardware platforms to discover whether key security properties and threat models can be extracted and used to create a security model from which the security of composed hardware can be validated. Further, given the dynamic nature of composed hardware, we will also investigate whether composed hardware can use dynamic verification mechanisms to assert security policy at runtime. Beginning with platforms composed using PCI express switches in which the devices of a host can be shared and allocated dynamically between hosts, we will investigate the evolving and increased flexibility from Compute Express Link (CXL) and its ability to remove the host and device hierarchy while permitting any compute element to be a host or device while also providing shared access across the platform. The objective outcome is to provide industry with a security model for a composed hardware platform from which security principles can be reasoned and demonstrated by its dynamic verification.

As IBM's 2nm chip is pushing Moore's law approaching its limit, conventional computing techniques are struggling to offer high performance computing within power consumption constraints. Inspired by the fault tolerance capability of the human brain, approximate computing, which is error tolerant, can offer a huge reduction in computer power consumption without affecting the results (such as accuracy) of certain human perception and recognition related computation that only require a result to be approximate, rather than accurate. Examples include Artificial Intelligence (AI), Deep Learning (DL), image processing and even some cryptographic schemes. However, approximate computing has been shown to have security vulnerabilities due to the unpredictability of intrinsic errors that may be indistinguishable from malicious modifications. Due to the inherent power and area savings achieved by approximate computing, security countermeasures shold also be lightweight ande efficient. Hence, the aim of this proposal is to use advanced hardware security techniques to enable the development of approximate computing technologies that have both optimal security protection and optimal system efficiency. Currently, no comprehensive research has been conducted to date into security of approximate computing or into countermeasures that protect such designs. Physical unclonable function (PUF), as a lightweight hardware security primitive, is one of the best candidates for securing resource-constrained applications, such as approximate computing. A PUF can be used to generate a unique digital fingerprint for an electronic device based on manufacturing process variations of silicon chips. Currently, PUFs have been widely studied for conventional computing but no effective intrinsic PUF designs using approximate techniques have been presented. This project is timely because approximate computing has rapidly attracted attention from both academica and industry, as it addresses one of the fundamental barriers in computing systems, power dissipation, but it has also opened new vectors of attacks. This project will develop an intrinsic PUF design based on the normal operations of an approximate processor without the need for addtional hardware resource. The project will aslo address for the first time how to achieve secure and effective approximate computing designs. Thales UK, a leader in designing and building mission-critical information systems for the defence, security, aerospace, and transportation sections, has already invited the PI to join the Thales CyRes-Advance project to investigate security protection for connected and autonomous vechicles (CAVs) by considering hardware security. Thales will provide £250k in-kind support, such as technical advice/review of the hardware design, access to Thales CAV test platform and experimental validation for the project, to accelerate the research process and produce high-quality research outputs.

We all critically depend on and use digital systems that sense and control physical processes and environments. Electricity, gas, water, and other utilities require the continuous operation of both national and local infrastructures to deliver their services. Industrial processes, for example for chemical manufacturing, production of materials such as cement, steel, aluminium or fertilizers, and manufacturing chains for car production or pharmaceuticals similarly lie at this intersection of the digital and the physical. This intersection also applies in other CPS such as robots, autonomous cars, and drones. All such systems are exposed to malicious threats and have been the target of cyber-attacks by different threat actors ranging from disgruntled employees to hacktivists, terrorists, organised crime and nation states. The increasing fragility and vulnerability of our cyber-enabled society is rapidly approaching intolerable limits. As these systems become larger and more complex interruption of service in any of these infrastructures can cause significant cascading effects with safety, economic and societal impacts. Because we critically depend on the operation of such systems, disruption to their operations must be minimised even when they are under attack and have been partially compromised. Because they operate in a physical environment, the safety of such systems must be preserved at all times to avoid physical damage and even threat to life. Therefore, ensuring the resilience of such systems, their survivability and continued operation when exposed to malicious threats requires the integration of methods and processes from security analysis, safety analysis, system design and operation that have traditionally been done separately and that each involve specialist skills and a significant amount of human effort. This is not only costly, but also error prone and delays response to security events. The full integration and automation of such methodologies will be a challenge for many years to come. However, RESICS aims to significantly advance the state-of-the-art and deliver novel contributions that facilitate: a) risk analysis for such systems in the face of adversarial threats taking into account the impact of security events across the cascading inter-dependencies; b) characterising attacks that can have an impact on the safety of the system, identifying the paths that make such attacks possible; c) identifying countermeasures that can be applied to mitigate threats and contain the impact of attacks; and d) ensuring that such countermeasures can be applied whilst preserving the system's safety and operational constraints and maximising its availability. These contributions will be evaluated across several test beds, digital twins, a cyber range and a number of use-cases across different industry sectors. They will deliver increased automation, lower the skill requirements involved in the analysis and in mitigating threats and improve response times to security incidents. To achieve these goals RESICS will combine model-driven and empirical approaches across both security and safety analysis, adopting a systems-thinking approach which emphasises Security, Safety and Resilience as emerging properties of the system. RESICS leverages preliminary results in the integration of safety and security methodologies with the application of formal methods and the combination of model-based and empirical approaches to the analysis of inter-dependencies in ICSs and CPSs.

Lasers are a key enabling technology in countless areas of modern society, touching on our lives in terms of ubiquitous connectivity, data storage, healthcare, security, environmental monitoring, etc. Examples include telecommunications, where they are used to generate the information carrying optical signals that are transmitted along thin glass optical fibres, manufacturing, where they are used for welding and cutting materials, and medicine, where they are used for sensing blood oxygen levels, and precisely resecting tissues. For almost all laser applications, it is necessary to use the laser source in combination with another technology that directs or "steers" the laser light in the desired direction. In some cases, this technology can be "passive", as is the case with the glass optical fibres used in telecommunications. In other cases, the steering technology must be "active" to change the direction of the laser beam in time, as is the case with the rapidly moving mirror systems used in some laser cutting and laser imaging systems. Conventional active laser steering technologies are often costly, bulky, and fragile. One or more of these disadvantages makes them sub-optimal for many important applications, including laser imaging systems for automotive applications, space-based laser communications systems, and drone-based remote sensing systems. To address this, there is currently a global drive to develop fully integrated solid-state beam-steering technologies, where the laser light is steered without the use of any physically moving components. Currently, however, even state-of-the-art solid-state laser beam steering systems have limited functionality, and do not meet the requirements of many real-world applications. In this project, we will exploit recent advances in two key integrated optical technologies - coherent Photonic Crystal Surface Emitting Laser (PCSEL) diode arrays and three-dimensional optical waveguide devices known as "integrated photonic lanterns" - to develop fully Integrated Solid-State Steerable Lasers (I-STEER) that can deliver agile beam steering in two dimensions and can, in principle, function at any diode laser wavelength. I-STEER will target the development of 900-mode PCSEL arrays, but will deliver the technological advances necessary to enable future PCSEL arrays (using commercial manufacturing facilities) that generate 10's of thousands of independently phase and ampltiude controllable coherent laser modes. A key aim of I-STEER is to enable denser PCSEL arrays, where the laser mode diameter is reduced to 20 microns (~20 wavelengths) and the centre-to-centre separation is reduced to ~50 microns (~50 wavelengths) - current PCSEL arrays exhibit 50 micron diameter laser modes with centre-to-centre separations of 400 microns. Unfortunately, even the ambitious spatial scales we are targeting mean that the PCSEL array will still be unsuitable for direct use as an optical phased array (OPA), since OPAs require very tightly packed wide angle emitters to achieve large angle/lobe free beam-steering. To address this, I-STEER introduces the fresh idea of using three-dimensional integrated optical waveguide transitions known as "integrated photonic lanterns" to adiabatically combine the PCSEL modes into a single highly multimode pattern of light, the spatial phase and amplitude properties of which can be directly controlled for beam steering via the PCSEL drive electronics. Through the I-STEER project, we aim to redefine the laser diode as an all-electronic integrated steerable light source enabling new functionally in countless applications including free-space optical communications and LiDAR. The generation of intellectual property and capability in this area will place the UK in a leading position with regards this strongly growing academic field, wealth generation through the creation of licensing and/or spin-outs, and in early adoption of UK based OEMs of this new technology.