Nazila Gol Mohammadi

Trustworthiness Attributes and Metrics for Engineering Trusted Internet-Based Software Systems

Trustworthiness of Internet-based software systems, apps, services and platform is a key success factor for their use and acceptance by organizations and end-users. The notion of trustworthiness, though, is subject to individual interpretation and preference, e.g., organizations require confidence about how their business critical data is handled whereas end-users may be more concerned about usability. As one main contribution, we present an extensive list of software quality attributes that contribute to trustworthiness. Those software quality attributes have been identified by a systematic review of the research literature and by analyzing two real-world use cases. As a second contribution, we sketch an approach for systematically deriving metrics to measure the trustworthiness of software system. Our work thereby contributes to better understanding which software quality attributes should be considered and assured when engineering trustworthy Internet-based software systems.

Maintaining trustworthiness of socio-technical systems at run-time

Trustworthiness of dynamical and distributed socio-technical systems is a key factor for the success and wide adoption of these systems in digital businesses. Different trustworthiness attributes should be identified and accounted for when such systems are built, and in order to maintain their overall trustworthiness they should be monitored during run-time. Trustworthiness monitoring is a critical task which enables providers to significantly improve the systems’ overall acceptance. However, trustworthiness characteristics are poorly monitored, diagnosed and assessed by existing methods and technologies. In this paper, we address this problem and provide support for semi-automatic trustworthiness maintenance. We propose a trustworthiness maintenance framework for monitoring and managing the system’s trustworthiness properties in order to preserve the overall established trust during run-time. The framework provides an ontology for run-time trustworthiness maintenance, and respective business processes for identifying threats and enacting control decisions to mitigate these threats. We also present use cases and an architecture for developing trustworthiness maintenance systems that support system providers.

A Framework for Combining Problem Frames and Goal Models to Support Context Analysis during Requirements Engineering

Quality requirements, like security requirements, are difficult to elicit, especially if they cross multiple domains. Understanding these domains is an important issue in the requirements engineering process for the corresponding systems. Well-known requirements engineering approaches, such as goal-oriented techniques provide a good starting point in capturing security requirements in the form of soft-goals in the early stage of the software engineering process. However, such approaches are not sufficient for context and problem analysis. On the other hand, the context and problem modeling approaches like e.g., problem frames, do not address the system goals. Integrating the relevant context knowledge into goal models is a promising approach to address the mutual limitations. In this paper, we propose a framework for combining goal models and problem frames. The framework makes it possible to document the goals of the system together with the corresponding knowledge of the system’s context. Furthermore, it supports the process of refining (soft-) goals right up to the elicitation of corresponding security requirements. To show the applicability of our approach, we illustrate its application on a real-life case study concerning Smart Grids.

Trustworthy Software Development

This paper presents an overview on how existing development methodologies and practices support the creation of trustworthy software. Trustworthy software is key for a successful and trusted usage of software, specifically in the Cloud. To better understand what trustworthy software applications actually mean, the concepts of trustworthiness and trust are defined and put in contrast to each other. Furthermore, we identify attributes of software applications that support trustworthiness. Based on this groundwork, some well-known software development methodologies and best practices are analyzed with respect on how they support the systematic engineering of trustworthy software. Finally, the state of the art is discussed in a qualitative way, and an outlook on necessary research efforts and technological innovations is given.

A Framework for Systematic Analysis and Modeling of Trustworthiness Requirements Using i* and BPMN

New technologies like cloud computing and new business models bring new capabilities for hosting and offering complex collaborative business operations. However, these advances can also bring undesirable side-effects, e.g., introducing new vulnerabilities and threats caused by collaboration and data exchange over the Internet. Hence, users become more concerned about the trust, e.g., trust in services for critical business processes with sensitive data. Since trust is subjective, trustworthiness requirements for addressing trust concerns are difficult to elicit, especially if there are different parties involved in the business process. In this paper, we propose a user-centered trustworthiness requirement analysis and modeling framework. Using goal models for capturing the users’ trust concerns can motivate design decisions with respect to trustworthiness. We purpose integrating the subjective trust concerns into goal models and embedding them into business process models as objective trustworthiness requirements. This paper addresses the gap in considering trustworthiness requirements during automation (in providing supporting software) of business processes. We demonstrate our approach on an application example from the health-care domain.

Towards Trustworthiness Assurance in the Cloud

Cloud- and service-oriented computing paradigms are intrinopaque to their users, as they cannot inspect providers’ implementations, and important concerns about aspects like security, compliance, dependability can arise. Therefore, users have to make trust decisions with respect to software providers, with the hope that there will not be any detrimental consequences. To contrast this situation, the paper proposes a framework to define, assess, monitor and make explicit the elements of a service that render it trustworthy. This paper relies on a number of recent scientific contributions, and aims at supporting informed decisions on obscure service implementations by machine-understandable statements about their objective (trustworthiness) characteristics. Such statements would innovate upon many aspects of service operations, from discovery to composition, deployment and monitoring. To demonstrate this, the paper presents a concept for a Trustworthy Service Marketplace.

Enhancing Business Process Models with Trustworthiness Requirements

The trustworthiness of systems that support complex collaborative business processes is an emergent property. In order to address users’ trust concerns, trustworthiness requirements of software systems must be elicited and satisfied. The aim of this paper is to address the gap that exists between end-users’ trust concerns and the lack of implementation of proper trustworthiness requirements in software systems. We focus on the challenges of specifying trustworthiness requirements and integrating them into the software development process as business process models. This paper provides a conceptual model of our approach by extending Business Process Model and Notation (BPMN) for integrating trustworthiness requirements. Our proposed approach explicitly considers the trustworthiness of individual components as part of the business process models. We use an application example from the health care domain to demonstrate our approach.

Evidence-Based Trustworthiness of Internet-Based Services Through Controlled Software Development

Users of Internet-based services are increasingly concerned about the trustworthiness of these services (i.e., apps, software, platforms) thus slowing down their adoption. Therefore, successful software development processes have to address trust concerns from the very early stages of development using constructive and practical methods to enable the trustworthiness of software and services. Unfortunately, even well-established development methodologies do not specifically support the realization of trustworthy Internet-based services today, and trustworthiness-oriented practices do not take objective evidences into account. We propose to use controlled software life-cycle processes for trustworthy Internet-based services. Development, deployment and operations processes, can be controlled by the collection of trustworthiness evidences at different stages. This can be achieved by e.g., measuring the degree of trustworthiness-related properties of the software, and documenting these evidences using digital trustworthiness certificates. This way, other stakeholders are able to verify the trustworthiness properties in a later stages, e.g., in the deployment of software on a marketplace, or the operation of the service at run-time.

Extending Development Methodologies with Trustworthiness-By-Design for Socio-Technical Systems

Socio-Technical Systems STS include humans, organizations, and the information systems that they use to achieve certain goals [1]. They are increasingly relevant for society, since advances in ICT technologies, such as cloud computing, facilitate their integration in our daily life. Due to the difficulty in preventing malicious attacks, vulnerabilities, or the misuse of sensitive information, users might not trust these systems. Trustworthiness in general can be defined as the assurance that the system will per-form as expected, or meets certain requirements cf., e.g. [2]. We consider trustworthiness as a multitude of quality attributes. As a means of constructive quality assurance, development methodologies should explicitly address the different challenges of building trustworthy software as well as evaluating trustworthiness, which is not supported by development methodologies, such as User-Centered Design UCD [3].

A Framework for Systematic Refinement of Trustworthiness Requirements

The trustworthiness of systems that support complex collaborative business processes is an emergent property. In order to address users’ trust concerns, trustworthiness requirements of software systems must be elicited and satisfied. The aim of this paper is to address the gap that exists between end-users’ trust concerns and the lack of implementation of proper trustworthiness requirements. New technologies like cloud computing bring new capabilities for hosting and offering complex collaborative business operations. However, these advances might bring undesirable side effects, e.g., introducing new vulnerabilities and threats caused by collaboration and data exchange over the Internet. Hence, users become more concerned about trust. Trust is subjective; trustworthiness requirements for addressing trust concerns are difficult to elicit, especially if there are different parties involved in the business process. We propose a user-centered trustworthiness requirement analysis and modeling framework. We integrate the subjective trust concerns into goal models and embed them into business process models as objective trustworthiness requirements. Business process model and notation is extended to enable modeling trustworthiness requirements. This paper focuses on the challenges of elicitation, refinement and modeling trustworthiness requirements. An application example from the healthcare domain is used to demonstrate our approach.