Towards Efficiency and Quality Assurance in Threat Analysis of Software Systems

Context: Security threats have been a growing concern in many organizations. Organizations developing software products strive to plan for security as soon as possible to mitigate such potential threats. In the design phase of the software development life-cycle, teams of experts routinely analyze the system architecture and design to nd potential security threats.Objective: The goal of this research is to improve on the performance of existing threat analysis techniques and support practitioners with automation and tool support. To understand the inner-workings of existing threat analysis methodologies we also conduct a systematic literature review examining 26 methodologies in detail. Our industrial partners conrm that existing techniques are labor intensive and do not provide quality guarantees about their outcomes.Method: We conducted empirical studies for building an in-depth understanding of existing techniques (Systematic Literature Review (SLR), controlled experiments). Further we rely on empirical case studies for ongoing validation of an attempted technique performance improvement.Findings: We have found that using a novel risk-rst approach can help reduce the labor while producing the same level of outcome quality in a shorter period of time. Further, we suggest that the key for a successful application of this approach is two fold. First, widening the analysis scope to end-to-end scenarios guides the analyst to focus on important assets. Second, appropriate model abstractions are required to manage the cognitive load of the human analysts. We have also found that reasoning about security in a formal setting requires extending the existing notations with security semantics. Further, minimal model extensions for doing so include security contracts for system nodes handling sensitive information. In such a setting, the analysis can be automated and can to some extent provide completeness guarantees.Future work: In the future, we plan to further study the analysis completeness guarantees. In particular, we plan to improve on the analysis automation and investigate complementary techniques for analysis completeness (namely informal pattern based techniques). We also plan to work on the disconnect between the planned and implemented security

A new, evidence-based, theory for knowledge reuse in security risk analysis

Security risk analysis (SRA) is a key activity in software engineering but requires heavy manual effort. Community knowledge in the form of security patterns or security catalogs can be used to support the identification of threats and security controls. However, no evidence-based theory exists about the effectiveness of security catalogs when used for security risk analysis. We adopt a grounded theory approach to propose a conceptual, revised and refined theory of SRA knowledge reuse. The theory refinement is backed by evidence gathered from conducting interviews with experts (20) and controlled experiments with both experts (15) and novice analysts (18). We conclude the paper by providing insights into the use of catalogs and managerial implications

A new, evidence-based, theory for knowledge reuse in security risk analysis

Security risk analysis (SRA) is a key activity in software engineering but requires heavy manual effort. Community knowledge in the form of security patterns or security catalogs can be used to support the identification of threats and security controls. However, no evidence-based theory exists about the effectiveness of security catalogs when used for security risk analysis. We adopt a grounded theory approach to propose a conceptual, revised and refined theory of SRA knowledge reuse. The theory refinement is backed by evidence gathered from conducting interviews with experts (20) and controlled experiments with both experts (15) and novice analysts (18). We conclude the paper by providing insights into the use of catalogs and managerial implications

Efficiency and Automation in Threat Analysis of Software Systems

Context: Security is a growing concern in many organizations. Industries developing software systems plan for security early-on to minimize expensive code refactorings after deployment. In the design phase, teams of experts routinely analyze the system architecture and design to find potential security threats and flaws. After the system is implemented, the source code is often inspected to determine its compliance with the intended functionalities. Objective: The goal of this thesis is to improve on the performance of security design analysis techniques (in the design and implementation phases) and support practitioners with automation and tool support.Method: We conducted empirical studies for building an in-depth understanding of existing threat analysis techniques (Systematic Literature Review, controlled experiments). We also conducted empirical case studies with industrial participants to validate our attempt at improving the performance of one technique. Further, we validated our proposal for automating the inspection of security design flaws by organizing workshops with participants (under controlled conditions) and subsequent performance analysis. Finally, we relied on a series of experimental evaluations for assessing the quality of the proposed approach for automating security compliance checks. Findings: We found that the eSTRIDE approach can help focus the analysis and produce twice as many high-priority threats in the same time frame. We also found that reasoning about security in an automated fashion requires extending the existing notations with more precise security information. In a formal setting, minimal model extensions for doing so include security contracts for system nodes handling sensitive information. The formally-based analysis can to some extent provide completeness guarantees. For a graph-based detection of flaws, minimal required model extensions include data types and security solutions. In such a setting, the automated analysis can help in reducing the number of overlooked security flaws. Finally, we suggested to define a correspondence mapping between the design model elements and implemented constructs. We found that such a mapping is a key enabler for automatically checking the security compliance of the implemented system with the intended design. The key for achieving this is two-fold. First, a heuristics-based search is paramount to limit the manual effort that is required to define the mapping. Second, it is important to analyze implemented data flows and compare them to the data flows stipulated by the design

Two architectural threat analysis techniques compared

In an initial attempt to systematize the research field of architectural threat analysis, this paper presents a comparative study of two threat analysis techniques. In particular, the controlled experiment presented here compares two variants of Microsoft’s STRIDE. The two variants differ in the way the analysis is performed. In one case, each component of the software system is considered in isolation and scrutinized for potential security threats. In the other case, the analysis has a wider scope and considers the security threats that might occur in a pair of interacting software components. The study compares the techniques with respect to their effectiveness in finding security threats (benefits) as well as the time that it takes to perform the analysis (cost). We also look into other human aspects which are important for industrial adoption, like, for instance, the perceived difficulty in learning and applying the techniques as well as the overall preference of our experimental participants