Software systems have an increasing impact on our daily lives. Many systems process sensitive data or control critical infrastructure. Providing secure software is therefore inevitable. Such systems are rarely being renewed regularly due to the high costs and effort. Oftentimes, systems that were planned and implemented to be secure, become insecure because their context evolves. These systems are connected to the Internet and therefore also constantly subject to new types of attacks. The security requirements of these systems remain unchanged, while, for example, discovery of a vulnerability of an encryption algorithm previously assumed to be secure requires a change of the system design. Some security requirements cannot be checked by the system’s design but only at run time. Furthermore, the sudden discovery of a security violation requires an immediate reaction to prevent a system shutdown. Knowledge regarding security best practices, attacks, and mitigations is generally available, yet rarely integrated part of software development or covering evolution.
This thesis examines how the security of long-living software systems can be preserved taking into account the influence of context evolutions. The goal of the proposed approach, S²EC²O, is to recover the security of model-based software systems using co-evolution.
An ontology-based knowledge base is introduced, capable of managing common, as well as system-specific knowledge relevant to security. A transformation achieves the connection of the knowledge base to the UML system model. By using semantic differences, knowledge inference, and the detection of inconsistencies in the knowledge base, context knowledge evolutions are detected.
A catalog containing rules to manage and recover security requirements uses detected context evolutions to propose potential co-evolutions to the system model which reestablish the compliance with security requirements.
S²EC²O uses security annotations to link models and executable code and provides support for run-time monitoring. The adaptation of running systems is being considered as is round-trip engineering, which integrates insights from the run time into the system model.
S²EC²O is amended by prototypical tool support. This tool is used to show S²EC²O’s applicability based on a case study targeting the medical information system iTrust.
This thesis at hand contributes to the development and maintenance of long-living software systems, regarding their security. The proposed approach will aid security experts: It detects security-relevant changes to the system context, determines the impact on the system’s security and facilitates co-evolutions to recover the compliance with the security requirements.
Although e-participation is becoming more and more important, security risks and requirements are so far only superficially regarded. This master thesis aims at contribute to security and privacy of e-participation applications. This paper deals with the users of electronic participation forms. Since personal data has to be transmitted in the e-participation process, systems require trustworthiness, privacy, transparency, availability and legal security between public administration and users. Therefore it is very important to ensure the most of security and privacy standards in information and communication technologies by the administration and the citizens to provide the necessary confidence in using e participation applications. This master thesis examines different e-participation platforms of the areas participatory budgeting, e-consultations, party websites, and e-petitions and explores at first which influence of sensitive e-participation systems on the political system they have. Subsequently, the current safety standard of the e-participation applications is determined. For this purpose an analysis framework is used, regarding on relevant security and privacy issues for e-participation. Based on the results safety levels are deduced from different types of e-participation applications. In addition recommendations for the constitution of e-participation are concluded, which helps to make e participation applications more secure. Furthermore, future technologies with the potential to improve security in the use of electronic public participation are presented.