Biblio

An often overlooked but equally important aspect of unmanned aerial system (UAS) design is the security of their networking protocols and how they deal with cyberattacks. In this context, cyberattacks are malicious attempts to monitor or modify incoming and outgoing data from the system. These attacks could target anywhere in the system where a transfer of data occurs but are most common in the transfer of data between the control station and the UAS. A compromise in the networking system of a UAS could result in a variety of issues including increased network latency between the control station and the UAS, temporary loss of control over the UAS, or a complete loss of the UAS. A complete loss of the system could result in the UAS being disabled, crashing, or the attacker overtaking command and control of the platform, all of which would be done with little to no alert to the operator. Fortunately, the majority of higher-end, enterprise, and government UAS platforms are aware of these threats and take actions to mitigate them. However, as the consumer market continues to grow and prices continue to drop, network security may be overlooked or ignored in favor of producing the lowest cost product possible. Additionally, these commercial off-the-shelf UAS often use uniform, standardized frequency bands, autopilots, and security measures, meaning a cyberattack could be developed to affect a wide variety of models with minimal changes. This paper will focus on a low-cost educational-use UAS and test its resilience to a variety of cyberattack methods, including man-in-the-middle attacks, spoofing of data, and distributed denial-of-service attacks. Following this experiment will be a discussion of current cybersecurity practices for counteracting these attacks and how they can be applied onboard a UAS. Although in this case the cyberattacks were tested against a simpler platform, the methods discussed are applicable to any UAS platform attempting to defend against such cyberattack methods.

The FAA proposes Safety Continuum that recognizes the public expectation for safety outcomes vary with aviation sectors that have different missions, aircraft, and environments. The purpose is to align the rigor of oversight to the public expectations. An aircraft, its variants or derivatives may be used in operations with different expectations. The differences in mission might bring immutable risks for some applications that reuse or revise the original aircraft type design. The continuum enables a more agile design approval process for innovations in the context of a dynamic ecosystems, addressing the creation of variants for different sectors and needs. Since an aircraft type design can be reused in various operations under part 91 or 135 with different mission risks the assurance case will have many branches reflecting the variants and derivatives.This paper proposes a model for the holistic, performance-based, through-life safety assurance case that focuses applicant and oversight alike on achieving the safety outcomes. This paper describes the application of goal-based, technology-neutral features of performance-based assurance cases extending the philosophy of UL 4600, to the Safety Continuum. This paper specifically addresses component reuse including third-party vehicle modifications and changes to operational concept or eco-system. The performance-based assurance argument offers a way to combine the design approval more seamlessly with the oversight functions by focusing all aspects of the argument and practice together to manage the safety outcomes. The model provides the context to assure mitigated risk are consistent with an operation’s place on the safety continuum, while allowing the applicant to reuse parts of the assurance argument to innovate variants or derivatives. The focus on monitoring performance to constantly verify the safety argument complements compliance checking as a way to assure products are "fit-for-use". The paper explains how continued operational safety becomes a natural part of monitoring the assurance case for growing variety in a product line by accounting for the ecosystem changes. Such a model could be used with the Safety Continuum to promote applicant and operator accountability delivering the expected safety outcomes.

Aviation is a highly sophisticated and complex System-of-Systems (SoSs) with equally complex safety oversight. As novel products with autonomous functions and interactions between component systems are adopted, the number of interdependencies within and among the SoS grows. These interactions may not always be obvious. Understanding how proposed products (component systems) fit into the context of a larger SoS is essential to promote the safe use of new as well as conventional technology.UL 4600, is a Standard for Safety for the Evaluation of Autonomous Products specifically written for completely autonomous Load vehicles. The goal-based, technology-neutral features of this standard make it adaptable to other industries and applications.This paper, using the philosophy of UL 4600, gives guidance for creating an assurance case for products in an SoS context. An assurance argument is a cogent structured argument concluding that an autonomous aircraft system possesses all applicable through-life performance and safety properties. The assurance case process can be repeated at each level in the SoS: aircraft, aircraft system, unmodified components, and modified components. The original Equipment Manufacturer (OEM) develops the assurance case for the whole aircraft envisioned in the type certification process. Assurance cases are continuously validated by collecting and analyzing Safety Performance Indicators (SPIs). SPIs provide predictive safety information, thus offering an opportunity to improve safety by preventing incidents and accidents. Continuous validation is essential for risk-based approval of autonomously evolving (dynamic) systems, learning systems, and new technology. System variants, derivatives, and components are captured in a subordinate assurance case by their developer. These variants of the assurance case inherently reflect the evolution of the vehicle-level derivatives and options in the context of their specific target ecosystem. These subordinate assurance cases are nested under the argument put forward by the OEM of components and aircraft, for certification credit.It has become a common practice in aviation to address design hazards through operational mitigations. It is also common for hazards noted in an aircraft component system to be mitigated within another component system. Where a component system depends on risk mitigation in another component of the SoS, organizational responsibilities must be stated explicitly in the assurance case. However, current practices do not formalize accounting for these dependencies by the parties responsible for design; consequently, subsequent modifications are made without the benefit of critical safety-related information from the OEMs. The resulting assurance cases, including 3rd party vehicle modifications, must be scrutinized as part of the holistic validation process.When changes are made to a product represented within the assurance case, their impact must be analyzed and reflected in an updated assurance case. An OEM can facilitate this by integrating affected assurance cases across their customer’s supply chains to ensure their validity. The OEM is expected to exercise the sphere-of-control over their product even if it includes outsourced components. Any organization that modifies a product (with or without assurance argumentation information from other suppliers) is accountable for validating the conditions for any dependent mitigations. For example, the OEM may manage the assurance argumentation by identifying requirements and supporting SPI that must be applied in all component assurance cases. For their part, component assurance cases must accommodate all spheres-of-control that mitigate the risks they present in their respective contexts. The assurance case must express how interdependent mitigations will collectively assure the outcome. These considerations are much more than interface requirements and include explicit hazard mitigation dependencies between SoS components. A properly integrated SoS assurance case reflects a set of interdependent systems that could be independently developed..Even in this extremely interconnected environment, stakeholders must make accommodations for the independent evolution of products in a manner that protects proprietary information, domain knowledge, and safety data. The collective safety outcome for the SoS is based on the interdependence of mitigations by each constituent component and could not be accomplished by any single component. This dependency must be explicit in the assurance case and should include operational mitigations predicated on people and processes.Assurance cases could be used to gain regulatory approval of conventional and new technology. They can also serve to demonstrate consistency with a desired level of safety, especially in SoSs whose existing standards may not be adequate. This paper also provides guidelines for preserving alignment between component assurance cases along a product supply chain, and the respective SoSs that they support. It shows how assurance is a continuous process that spans product evolution through the monitoring of interdependent requirements and SPI. The interdependency necessary for a successful assurance case encourages stakeholders to identify and formally accept critical interconnections between related organizations. The resulting coordination promotes accountability for safety through increased awareness and the cultivation of a positive safety culture.

Over the past decade, the reliance on Unmanned Aerial Systems (UAS) to carry out critical missions has grown drastically. With an increased reliance on UAS as mission assets and the dependency of UAS on cyber resources, cyber security of UAS must be improved by adopting sound security principles and relevant technologies from the computing community. On the other hand, the traditional avionics community, being aware of the importance of cyber security, is looking at new architecture and designs that can accommodate both the traditional safety oriented principles as well as the cyber security principles and techniques. It is with the effective and timely convergence of these domains that a holistic approach and co-design can meet the unique requirements of modern systems and operations. In this paper, authors from both the cyber security and avionics domains describe our joint effort and insights obtained during the course of designing secure and resilient embedded avionics systems.

In recent years, the usage of unmanned aircraft systems (UAS) for security-related purposes has increased, ranging from military applications to different areas of civil protection. The deployment of UAS can support security forces in achieving an enhanced situational awareness. However, in order to provide useful input to a situational picture, sensor data provided by UAS has to be integrated with information about the area and objects of interest from other sources. The aim of this study is to design a high-level data fusion component combining probabilistic information processing with logical and probabilistic reasoning, to support human operators in their situational awareness and improving their capabilities for making efficient and effective decisions. To this end, a fusion component based on the ISR (Intelligence, Surveillance and Reconnaissance) Analytics Architecture (ISR-AA) [1] is presented, incorporating an object-oriented world model (OOWM) for information integration, an expressive knowledge model and a reasoning component for detection of critical events. Approaches for translating the information contained in the OOWM into either an ontology for logical reasoning or a Markov logic network for probabilistic reasoning are presented.

Cyber-Physical Systems (CPS) such as Unmanned Aerial Systems (UAS) sense and actuate their environment in pursuit of a mission. The attack surface of these remotely located, sensing and communicating devices is both large, and exposed to adversarial actors, making mission assurance a challenging problem. While best-practice security policies should be followed, they are rarely enough to guarantee mission success as not all components in the system may be trusted and the properties of the environment (e.g., the RF environment) may be under the control of the attacker. CPS must thus be built with a high degree of resilience to mitigate threats that security cannot alleviate. In this paper, we describe the Agile and Resilient Embedded Systems (ARES) methodology and metric set. The ARES methodology pursues cyber security and resilience (CSR) as high level system properties to be developed in the context of the mission. An analytic process guides system developers in defining mission objectives, examining principal issues, applying CSR technologies, and understanding their interactions.

Unmanned Aerial Systems (UAS) have raised a great concern on privacy recently. A practical method to protect privacy is needed for adopting UAS in civilian airspace. This paper examines the privacy policies, filtering strategies, existing techniques, then proposes a novel method based on the encrypted video stream and the cloud-based privacy servers. In this scheme, all video surveillance images are initially encrypted, then delivered to a privacy server. The privacy server decrypts the video using the shared key with the camera, and filters the image according to the privacy policy specified for the surveyed region. The sanitized video is delivered to the surveillance operator or anyone on the Internet who is authorized. In a larger system composed of multiple cameras and multiple privacy servers, the keys can be distributed using Kerberos protocol. With this method the privacy policy can be changed on demand in real-time and there is no need for a costly on-board processing unit. By utilizing the cloud-based servers, advanced image processing algorithms and new filtering algorithms can be applied immediately without upgrading the camera software. This method is cost-efficient and promotes video sharing among multiple subscribers, thus it can spur wide adoption.