Biblio

The Department of Defense (DoD) manages capabilities through the Joint Interoperability and Capability Development System (JCIDS) process. As part of this process, sponsors develop a series of DoD Architecture Framework (DoDAF) products to assist analysts understand the proposed capability and how it fits into the broader network of DoD legacy systems and systems under development. However, the Joint Staff, responsible for executing the JCIDS process, often analyzes these architectures in isolation without considering the broader network of systems. DoD leadership, the Government Accountability Organization, and others have noted the lack of the DoD's ability to manage the broader portfolio of capabilities in various reports and papers. Several efforts have proposed merging DoDAF architecture into a larger meta-architecture based on individual system architectures. This paper specifically targets the Systems View 3 (SV-3), System-to-system matrix, as an opportunity to merge multiple DoDAF architecture views into a network of system and understand the potential benefits associated with analyzing a broader perspective. The goal of merging multiple SV-3s is to better understand the interoperability of a system within the network of DoD systems as network metrics may provide insights into the relative interoperability of a DoD system. Currently, the DoD's definition of interoperability focuses on the system or capability's ability to enter and operate within the DoD Information Network (DoDIN); however, this view limits the definition of interoperability as it focuses solely on information flows and not resource flows or physical connections that should be present in a SV-3. The paper demonstrates the importance of including all forms of connections between systems in a network by comparing network metrics associated with the different types of connections. Without a complete set of DoDAF architectures for each system within the DoD and based on the potential classification of these products, the paper collates data that should be included in an SV-3 from open source, unclassified references to build the overall network of DoD systems. From these sources, a network of over 300 systems with almost 1000 connections emerges based on the documented information, resource, and physical connections between these legacy and planned DoD systems. With this network, the paper explores the quantification of individual system's interoperability through the application of nodal and network metrics from social network analysis (SNA). A SNA perspective on a network of systems provides additional insights beyond traditional network analysis because of the emphasis on the importance of nodes, systems, in the network as well as the relationship, connections, between the nodes. Finally, the paper proposes future work to explore the quantification of additional attributes of systems as well as a method for further validating the findings.

Opportunities arising from IoT-enabled applications are significant, but market growth is inhibited by concerns over security and complexity. To address these issues, we propose the ERAMIS methodology, which is based on instantiation of a reference architecture that captures common design features, embodies best practice, incorporates good security properties by design, and makes explicit provision for operational security services and processes.

The defense-in-depth approach has been widely recommended for designing critical information infrastructure, however, the lack of holistic design guidelines makes it difficult for many organizations to adopt the concept. Therefore, this paper proposes a holistic architectural framework and guidelines based on ring-based nested network zones for designing such highly secured information systems. This novel security architectural framework and guidelines offer the overall structural design and implementation options for holistically designing the N-tier/shared nothing system architectures. The implementation options, e.g. for the zone's perimeters, are recommended to achieve different capability levels of security or to trade off among different required security attributes. This framework enables the adaptive capability suitable for different real-world contexts. This paper also proposes an attack-hops verification approach as a tool to evaluate the architectural design.

Cloud-based cyber-physical systems, like vehicle and intelligent transportation systems, are now attracting much more attentions. These systems usually include large-scale distributed sensor networks covering various components and producing enormous measurement data. Lots of modeling languages are put to use for describing cyber-physical systems or its aspects, bringing contribution to the development of cyber-physical systems. But most of the modeling techniques only focuse on software aspect so that they could not exactly express the whole cloud-based cyber-physical systems, which require appropriate views and tools in its design; but those tools are hard to be used under systemic or object-oriented methods. For example, the widest used modeling language, UML, could not fulfil the above design's requirements by using the foremer's standard form. This paper presents a method designing the cloud-based cyber-physical systems with AADL, by which we can analyse, model and apply those requirements on cloud platforms ensuring QoS in a relatively highly extensible way at the mean time.

In the component-based software system, certain behaviours of components and their composition may affect system reliability at runtime. This problem can be early detected through the automated verification of software architecture design, by which model checking is one of the techniques to achieve this. However, its practicality and performance issue remain challenges. This paper presents a scalable approach for the software architecture verification. The modelling is proposed to manifest the behaviours in the software component, in order to detect problematic behaviours, such as circular dependency and performance bottleneck. The outcome of the verification identifies the problem and the scenarios that cause it. In order to mitigate the verification performance issue, the parallelism is applied to the verification process so that multiple decomposed models can be simultaneously verified on a multi-threaded environment. As some software systems are designed as the monolithic architecture, we present a method that helps to automatically decompose a large monolithic model into a set of smaller sub-models. Our approach was evaluated and proved to enhance the performance of the verification process for the large-scale complex software systems.

Processing smart grid data for analytics purposes brings about a series of privacy-related risks. In order to allow for the most suitable mitigation strategies, reasonable privacy risks need to be addressed by taking into consideration the perspective of each smart grid stakeholder separately. In this context, we use the notion of privacy concerns to reflect potential privacy risks from the perspective of different smart grid stakeholders. Privacy concerns help to derive privacy goals, which we represent using the goals structuring notation. Thus represented goals can more comprehensibly be addressed through technical and non-technical strategies and solutions. The thread of argumentation - from concerns to goals to strategies and solutions - is presented in form of a privacy case, which is analogous to the safety case used in the automotive domain. We provide an exemplar privacy case for the smart grid developed as part of the Aspern Smart City Research project.

With the recent proliferation of Internet of Things (IoT) and embedded devices, there is a growing need to develop a security framework to protect such devices. RISC-V is a promising open source architecture that targets low-power embedded devices and SoCs. However, there is a dearth of practical and low-overhead security solutions in the RISC-V architecture. Programs compiled using RISC-V toolchains are still vulnerable to code injection and code reuse attacks such as buffer overflow and return-oriented programming (ROP). In this paper, we propose FIXER, a hardware implemented security extension to RISC-V that provides a defense mechanism against such attacks. FIXER enforces fine-grained control-flow integrity (CFI) of running programs on backward edges (returns) and forward edges (calls) without requiring any architectural modifications to the RISC-V processor core. We implement FIXER on RocketChip, a RISC-V SoC platform, by leveraging the integrated Rocket Custom Coprocessor (RoCC) to detect and prevent attacks. Compared to existing software based solutions, FIXER reduces energy overhead by 60% at minimal execution time (1.5%) and area (2.9%) overheads.

Cyber-Physical Systems (CPS) attract growing interest from architects and attackers, given their potential effect on privacy and safety of ecosystems and users. Architectural tactics have been proposed as a design-time abstraction useful to guide and evaluate systems design decisions that address specific system qualities, but there is little published evidence of how Security Tactics help to mitigate security threats in the context of Cyber-Physical Systems. This article reports the principled derivation of architectural tactics for an actual SCADA-SAP bridge, where security was the key concern; the key inputs were (1) a well-known taxonomies of architectural tactics, and (2) a detailed record of trade-offs among these tactics. The project architects used client-specified quality attributes to identify relevant tactics in the taxonomy, and information on their trade-offs to guide top-level decisions on system global shape. We venture that all architectural tactics taxonomies should be enriched with explicit trade-offs, allowing architects to compare alternative solutions that seem equally good on principle but are not so in practice.

Medical Internet of Things (MIoT) offers innovative solutions to a healthier life, making radical changes in people's lives. Healthcare providers are enabled to continuously and remotely monitor their patients for many medial issues outside hospitals and healthcare providers' offices. MIoT systems and applications lead to increase availability, accessibility, quality and cost-effectiveness of healthcare services. On the other hand, MIoT devices generate a large amount of diverse real-time data, which is highly sensitive. Thus, securing medical data is an essential requirement when developing MIoT architectures. However, the MIoT architectures being developed in the literature have many security issues. To address the challenge of data security in MIoT, the integration of fog computing and MIoT is studied as an emerging and appropriate solution. By data security, it means that medial data is stored in fog nodes and transferred to the cloud in a secure manner to prevent any unauthorized access. In this paper, we propose a design for a secure fog-cloud based architecture for MIoT.

Microservice Architectures (MSA) structure applications as a collection of loosely coupled services that implement business capabilities. The key advantages of MSA include inherent support for continuous deployment of large complex applications, agility and enhanced productivity. However, studies indicate that most MSA are homogeneous, and introduce shared vulnerabilites, thus vulnerable to multi-step attacks, which are economics-of-scale incentives to attackers. In this paper, we address the issue of shared vulnerabilities in microservices with a novel solution based on the concept of Moving Target Defenses (MTD). Our mechanism works by performing risk analysis against microservices to detect and prioritize vulnerabilities. Thereafter, security risk-oriented software diversification is employed, guided by a defined diversification index. The diversification is performed at runtime, leveraging both model and template based automatic code generation techniques to automatically transform programming languages and container images of the microservices. Consequently, the microservices attack surfaces are altered thereby introducing uncertainty for attackers while reducing the attackability of the microservices. Our experiments demonstrate the efficiency of our solution, with an average success rate of over 70% attack surface randomization.

In the development process of critical systems, one of the main challenges is to provide early system validation and verification against vulnerabilities in order to reduce cost caused by late error detection. We propose in this paper an approach that, firstly allows formally describe system security specifications, thanks to our suggested extended attack tree. Secondly, static and dynamic system modeling by using a SysML connectivity profile to model error propagation is introduced. Finally, a model checker has been used in order to validate system specifications.

An important principle in computational security is to reduce the attack surface, by maintaining the Trusted Computing Base (TCB) small. Even so, no security technique ensures full protection against any adversary. Thus, sensitive applications should be designed with several layers of protection so that, even if a layer might be violated, sensitive content will not be compromised. In 2015, Intel released the Software Guard Extensions (SGX) technology in its processors. This mechanism allows applications to allocate enclaves, which are private memory regions that can hold code and data. Other applications and even privileged code, like the OS kernel and the BIOS, are not able to access enclaves' contents. This paper presents a novel password file protection scheme, which uses Intel SGX to protect authentication credentials in the PAM authentication framework, commonly used in UNIX systems. We defined and implemented an SGX-enabled version of the pam\_unix.so authentication module, called UniSGX. This module uses an SGX enclave to handle the credentials informed by the user and to check them against the password file. To add an extra security layer, the password file is stored using SGX sealing. A threat model was proposed to assess the security of the proposed solution. The obtained results show that the proposed solution is secure against the threat model considered, and that its performance overhead is acceptable from the user point of view. The scheme presented here is also suitable to other authentication frameworks.

Security issues emerging out of the constantly evolving software applications became a huge challenge to software security experts. In this paper, we propose a prototype to detect vulnerabilities by identifying their architectural sources and also use security patterns to mitigate the identified vulnerabilities. We emphasize the need to consider architectural relations to introduce an effective security solution. In this research, we focused on the taint-style vulnerabilities that can induce injection-based attacks like XSS, SQLI in web applications. With numerous tools available to detect the taint-style vulnerabilities in the web applications, we scanned for the presence of repetition of a vulnerable code pattern in the software. Very importantly, we attempted to identify the architectural source files or modules by developing a tool named ArT Analyzer. We conducted a case study on a leading health-care software by applying the proposed architectural taint analysis and identified the vulnerable spots. We could identify the architectural roots for those vulnerable spots with the use of our tool ArT Analyzer. We verified the results by sharing it with the lead software architect of the project. By adopting an architectural solution, we avoided changes to be done on 252 different lines of code by merely introducing 2 lines of code changes at the architectural roots. Eventually, this solution was integrated into the latest updated release of the health-care software.

This paper proposes an architecture of Secure Shell (SSH) honeypot using port knocking and Intrusion Detection System (IDS) to learn the information about attacks on SSH service and determine proper security mechanisms to deal with the attacks. Rapid development of information technology is directly proportional to the number of attacks, destruction, and data theft of a system. SSH service has become one of the popular targets from the whole vulnerabilities which is existed. Attacks on SSH service have various characteristics. Therefore, it is required to learn these characteristics by typically utilizing honeypots so that proper mechanisms can be applied in the real servers. Various attempts to learn the attacks and mitigate them have been proposed, however, attacks on SSH service are kept occurring. This research proposes a different and effective strategy to deal with the SSH service attack. This is done by combining port knocking and IDS to make the server keeps the service on a closed port and open it under user demand by sending predefined port sequence as an authentication process to control the access to the server. In doing so, it is evident that port knocking is effective in protecting SSH service. The number of login attempts obtained by using our proposed method is zero.

The recently applied General Data Protection Regulation (GDPR) aims to protect all EU citizens from privacy and data breaches in an increasingly data-driven world. Consequently, this deeply affects the factory domain and its human-centric automation paradigm. Especially collaboration of human and machines as well as individual support are enabled and enhanced by processing audio and video data, e.g. by using algorithms which re-identify humans or analyse human behaviour. We introduce most significant impacts of the recent legal regulation change towards the automations domain at a glance. Furthermore, we introduce a representative scenario from production, deduce its legal affections from GDPR resulting in a privacy-aware software architecture. This architecture covers modern virtualization techniques along with authorization and end-to-end encryption to ensure a secure communication between distributes services and databases for distinct purposes.

As an extension of cloud computing, fog computing is proving itself more and more potentially useful nowadays. Fog computing is introduced to overcome the shortcomings of cloud computing paradigm in handling the massive amount of traffic caused by the enormous number of Internet of Things devices being increasingly connected to the Internet on daily basis. Despite its advantages, fog architecture introduces new security and privacy threats that need to be studied and solved as soon as possible. In this work, we explore two privacy issues posed by the fog computing architecture and we define privacy challenges according to them. The first challenge is related to the fog's design purposes of reducing the latency and improving the bandwidth, where the existing privacy-preserving methods violate these design purposed. The other challenge is related to the proximity of fog nodes to the end-users or IoT devices. We discuss the importance of addressing these challenges by putting them in the context of real-life scenarios. Finally, we propose a privacy-preserving fog computing paradigm that solves these challenges and we assess the security and efficiency of our solution.

Current technologies to include cloud computing, social networking, mobile applications and crowd and synthetic intelligence, coupled with the explosion in storage and processing power, are evolving massive-scale marketplaces for a wide variety of resources and services. They are also enabling unprecedented forms and levels of collaborations among human and machine entities. In this new era, trust remains the keystone of success in any relationship between two or more parties. A primary challenge is to establish and manage trust in environments where massive numbers of consumers, providers and brokers are largely autonomous with vastly diverse requirements, capabilities, and trust profiles. Most contemporary trust management solutions are oblivious to diversities in trustors' requirements and contexts, utilize direct or indirect experiences as the only form of trust computations, employ hardcoded trust computations and marginally consider collaboration in trust management. We surmise the need for reference architecture for trust management to guide the development of a wide spectrum of trust management systems. In our previous work, we presented a preliminary reference architecture for trust management which provides customizable and reconfigurable trust management operations to accommodate varying levels of diversity and trust personalization. In this paper, we present a comprehensive taxonomy for trust management and extend our reference architecture to feature collaboration as a first-class object. Our goal is to promote the development of new collaborative trust management systems, where various trust management operations would involve collaborating entities. Using the proposed architecture, we implemented a collaborative personalized trust management system. Simulation results demonstrate the effectiveness and efficiency of our system.

Cloud Computing represents one of the most significant shifts in information technology and it enables to provide cloud-based security service such as Security-as-a-service (SECaaS). Improving of the cloud computing technologies, the traditional SIEM paradigm is able to shift to cloud-based security services. In this paper, we propose the SIEM architecture that can be deployed to the SECaaS platform which we have been developing for analyzing and recognizing intelligent cyber-threat based on virtualization technologies.

This paper introduces a newly developed Object-Oriented Open Software Architecture designed for supporting security applications, while leveraging on the capabilities offered by dedicated Open Hardware devices. Specifically, we target the SEcube™ platform, an Open Hardware security platform based on a 3D SiP (System on Package) designed and produced by Blu5 Group. The platform integrates three components employed for security in a single package: a Cortex-M4 CPU, a FPGA and an EAL5+ certified Smart Card. The Open Software Architecture targets both the host machine and the security device, together with the secure communication among them. To maximize its usability, this architecture is organized in several abstraction layers, ranging from hardware interfaces to device drivers, from security APIs to advanced applications, like secure messaging and data protection. We aim at releasing a multi-platform Open Source security framework, where software and hardware cooperate to hide to both the developer and the final users classical security concepts like cryptographic algorithms and keys, focusing, instead, on common operational security concepts like groups and policies.

Smart Internet of Things (IoT) applications will rely on advanced IoT platforms that not only provide access to IoT sensors and actuators, but also provide access to cloud services and data analytics. Future IoT platforms should thus provide connectivity and intelligence. One approach to connecting IoT devices, IoT networks to cloud networks and services is to use network federation mechanisms over the internet to create network slices across heterogeneous platforms. Network slices also need to be protected from potential external and internal threats. In this paper we describe an approach for enforcing global security policies in the federated cloud and IoT networks. Our approach allows a global security to be defined in the form of a single service manifest and enforced across all federation network segments. It relies on network function virtualisation (NFV) and service function chaining (SFC) to enforce the security policy. The approach is illustrated with two case studies: one for a user that wishes to securely access IoT devices and another in which an IoT infrastructure administrator wishes to securely access some remote cloud and data analytics services.

Active authentication is the problem of continuously verifying the identity of a person based on behavioral aspects of their interaction with a computing device. In this paper, we collect and analyze behavioral biometrics data from 200 subjects, each using their personal Android mobile device for a period of at least 30 days. This data set is novel in the context of active authentication due to its size, duration, number of modalities, and absence of restrictions on tracked activity. The geographical colocation of the subjects in the study is representative of a large closed-world environment such as an organization where the unauthorized user of a device is likely to be an insider threat: coming from within the organization. We consider four biometric modalities: 1) text entered via soft keyboard, 2) applications used, 3) websites visited, and 4) physical location of the device as determined from GPS (when outdoors) or WiFi (when indoors). We implement and test a classifier for each modality and organize the classifiers as a parallel binary decision fusion architecture. We are able to characterize the performance of the system with respect to intruder detection time and to quantify the contribution of each modality to the overall performance.

Detecting software security vulnerabilities and distinguishing vulnerable from non-vulnerable code is anything but simple. Most of the time, vulnerabilities remain undisclosed until they are exposed, for instance, by an attack during the software operational phase. Software metrics are widely-used indicators of software quality, but the question is whether they can be used to distinguish vulnerable software units from the non-vulnerable ones during development. In this paper, we perform an exploratory study on software metrics, their interdependency, and their relation with security vulnerabilities. We aim at understanding: i) the correlation between software architectural characteristics, represented in the form of software metrics, and the number of vulnerabilities; and ii) which are the most informative and discriminative metrics that allow identifying vulnerable units of code. To achieve these goals, we use, respectively, correlation coefficients and heuristic search techniques. Our analysis is carried out on a dataset that includes software metrics and reported security vulnerabilities, exposed by security attacks, for all functions, classes, and files of five widely used projects. Results show: i) a strong correlation between several project-level metrics and the number of vulnerabilities, ii) the possibility of using a group of metrics, at both file and function levels, to distinguish vulnerable and non-vulnerable code with a high level of accuracy.

Service composition is currently done by (hierarchical) orchestration and choreography. However, these approaches do not support explicit control flow and total compositionality, which are crucial for the scalability of service-oriented systems. In this paper, we propose exogenous connectors for service composition. These connectors support both explicit control flow and total compositionality in hierarchical service composition. To validate and evaluate our proposal, we present a case study based on the popular MusicCorp.

Access to computer systems and the information held on them, be it commercially or personally sensitive, is naturally, strictly controlled by both legal and technical security measures. One such method is digital identity, which is used to authenticate and authorize users to provide access to IT infrastructure to perform official, financial or sensitive operations within organisations. However, transmitting and sharing this sensitive information with other organisations over insecure channels always poses a significant security and privacy risk. An example of an effective solution to this problem is the Federated Identity Management (FIdM) standard adopted in the cloud environment. The FIdM standard is used to authenticate and authorize users across multiple organisations to obtain access to their networks and resources without transmitting sensitive information to other organisations. Using the same authentication and authorization details among multiple organisations in one federated group, it protects the identities and credentials of users in the group. This protection is a balance, mitigating security risk whilst maintaining a positive experience for users. Three of the most popular FIdM standards are Security Assertion Markup Language (SAML), Open Authentication (OAuth), and OpenID Connect (OIDC). This paper presents an assessment of these standards considering their architectural design, working, security strength and security vulnerability, to cognise and ascertain effective usages to protect digital identities and credentials. Firstly, it explains the architectural design and working of these standards. Secondly, it proposes several assessment criteria and compares functionalities of these standards based on the proposed criteria. Finally, it presents a comprehensive analysis of their security vulnerabilities to aid in selecting an apposite FIdM. This analysis of security vulnerabilities is of great significance because their improper or erroneous deployme- t may be exploited for attacks.

Creating and implementing fault-tolerant distributed algorithms is a challenging task in highly safety-critical industries. Using formal methods supports design and development of complex algorithms. However, formal methods are often perceived as an unjustifiable overhead. This paper presents the experience and insights when using TLA+ and PlusCal to model and develop fault-tolerant and safety-critical modules for TAS Control Platform, a platform for railway control applications up to safety integrity level (SIL) 4. We show how formal methods helped us improve the correctness of the algorithms, improved development efficiency and how part of the gap between model and implementation has been closed by translation to C code. Additionally, we describe how we gained trust in the formal model and tools by following a specific design process called property-driven design, which also implicitly addresses software quality metrics such as code coverage metrics.