As any software system, a self-adaptive system is subject to security threats. However, applying self-adaptation may introduce additional threats. So far, little research has been devoted to this important problem. In this paper, we propose an approach for vulnerability analysis of architecture-based adaptations in self-adaptive systems using threat modeling and analysis techniques. To this end, we specify components' vulnerabilities and the system architecture formally and generate an attack model that describes the attacker's strategies to attack the system by exploiting different vulnerabilities. We use a set of security metrics to quantitatively assess the security risks of adaptations based on the produced attack model which enables the system to consider security aspects while choosing an adaptation to apply to the system. We automate and incorporate our approach into the Rainbow framework, allowing for secure architectural adaptations at runtime. To evaluate the effectiveness of our approach, we apply it on a simple document storage system and on the ZNN system.

As threats to computer security become more common, complex and frequent, systems that canautomatically protect themselves from attacks are imminently needed. In this paper, we proposea formal approach to achieve self-protection by performing security analysis on self-adaptive systems, taking the adaptation process into account. We use probabilistic model checking to quantitatively analyze adaptation security, rank the strategies available and select the most secure one to apply in the system. We have incorporated our approach in Rainbow which is a framework to develop architecture-based self-adaptive systems.To evaluate our approach's effectiveness, we applied it on two  case studies: a simple document storage system and ZNN, a well known self-adaptive exemplar. The results show that applying our approachcan guarantee a reasonable degree of security, both during and after adaptation.

Modern software systems are decentralized, distributed, and dynamic, and consequently, require decentralized mechanisms to enforce security. In this paper, we propose an adaptive approach using a combination of decentralized information flow control (DIFC) mechanisms, trust-based methods and decentralized control architectures to enforce security in open distributed systems. In our approach, adaptivity mitigates two aspects of the system dynamics that cause uncertainty: the ever-changing nature of trust and system openness. We formalize our trust-aware DIFC model and instantiate two decentralized control architectures to implement and evaluate it. We evaluate the effectiveness and performance of our method and decentralized control architectures on two case studies.

Modern software systems and their corresponding architectures are increasingly decentralized, distributed, and dynamic. As a consequence, decentralized mechanisms are required to ensure security in such architectures. Decentralized Information Flow Control (DIFC) is a mechanism to control information flow in distributed systems. This article presents and discusses several improvements to an adaptive decentralized information flow approach that incorporates trust for decentralized systems to provide security. Adaptive Trust-Aware Decentralized Information Flow (AT-DIFC+) combines decentralized information flow control mechanisms, trust-based methods, and decentralized control architectures to control and enforce information flow in an open, decentralized system. We strengthen our approach against newly discovered attacks and provide additional information about its reconfiguration, decentralized control architectures, and reference implementation. We evaluate the effectiveness and performance of AT-DIFC+ on two case studies and perform additional experiments and to gauge the mitigations’ effectiveness against the identified attacks.

Given the increasing complexity of software-intensive systems as well as the sophistication and high frequencyof cyber-attacks, automated and sound approaches to select countermeasures are required to effectively protect softwaresystems. In this paper, we propose a formal architecture-centered approach to analyze the security of a software-intensive component-based system to find cost-efficient countermeasuresthat consider both the system architecture and its behavior. We evaluate our approach by applying it on a case study.

To reason about and enforce security in complex, dynamic software systems, automated  analysis and verification approaches are required.Such approaches, however, often suffer from  scalability issues when employed at runtime. In this work, we propose an automated formal approach for security analysis of component-based systems that exploits formal abstraction and incremental analysis techniques to reduce the complexity of runtime analysis.We have fully automated, implemented and evaluated our approach. Our experiment results show that our approach indeed reduces the verification complexity.