The implied need for security and connected requirements by the use of e-learning systems has only been marginally examined up to now. A problem of respective research is given by the relation of abstract criteria and requirements from educational science with technical realisation possibilities from informatics subdomains. The research project as presented in this thesis focuses on this interdisciplinary field and investigates e-learning from perspectives of both disciplines to develop a security concept that provides a sufficient level of security without negatively influencing the learning process. This thesis, first, deals with the question of which data and functionality for teaching with e-learning systems are reasonable. For this, design criteria for e-learning basing on educational scientific findings are deduced and brought into relation with aspects of information security.
Special consideration is put into the learning process and specific requirements of learners in order to prioritise learning in opposition to the pure use of informatics systems. Requirements for an appropriate processing and storing of needed data and functionality are discussed.
Core component of this work is the investigation of threats for e-learning by using the fault tree analysis approach. To conduct this analysis, certain demands resulting from educational science and e-learning research are transferred to technical assets. These assets, thereafter, can be used as root elements of subtrees within the fault tree analysis, i.e., harming such assets is considered to be an undesired event that should be avoided. During the threat analysis process, dependencies on base components of e-learning as web-based service are also considered and discussed, e.g., web server or database system. A central aspect of this analysis is given by mutual dependencies and different expectations of affiliated roles and groups of users in those roles. Exemplary threats, as discovered within the analysis step, are discussed with possible consequences and relevance for e-learning. The entire fault tree is presented in the appendix of this thesis. In addition to the theoretical investigation, case studies of wide-spread and well-known learning management systems are presented that demonstrate different practical shortcomings in the security concepts of these systems. This thesis primarily deals with conceptual problems in the software design, i.e., threats by abusing functionality that was meant to be present in the software. These shortcomings in design imply a significant challenge for mitigation, such that the necessity of an early integration of security deliberations and recommendations into e-learning systems gets emphasised.
Basing on discovered threats for e-learning, respective recommendations are introduced and discussed that can help avoiding the majority of mentioned problems and threats. Knowing that security mechanisms may require user interaction, and therefore, can distract learners from their learning process, a proxy server approach is presented. This proxy server can overtake user interactions following predefined rules. Thus, the user can be relieved despite the implementation of sophisticated security mechanisms. A respective architecture, specification details, and realisation deliberations are discussed together with related problems. This thesis is concluded by a discussion of achieved results and open problems.