A service mesh is a dedicated infrastructure layer that facilitates secure, reliable communication between services in a distributed system. HAFAS is a distributed off-the-shelf timetable information system maintained by Hacon, a Siemens Mobility subsidiary. Introducing a service mesh to HAFAS is a base scenario for a call of research to understand better the requirements and impacts of a service mesh on distributed systems.

This thesis examines introducing a service mesh to a distributed software system and investigates the impact on the example of HAFAS. Scenarios for HAFAS that profit from the features of a service mesh were identified and mapped to functional requirements. The service mesh technological landscape was investigated by defining additional non-functional requirements and identifying a project satisfying the requirements. A subset of prioritized scenarios emerged after investigating the previous scenarios more closely in the context of the identified service mesh project.

By introducing the identified service mesh project and the scenario subset to a HAFAS environment as a case study, valuable data on the feasibility of the operation has arisen. The resulting data allowed the investigation of value added by the service mesh and impacts on latency and resource consumption. Data analysis showed that introducing a service mesh has an acceptable impact on latency, memory, and CPU resources. The benefits gained through mTLS encryption improve the system’s overall security by introducing the security properties of confidentiality, integrity, and authenticity to HAFAS’s data in transit.

The results of this thesis help organizations that plan on adopting a service mesh to their technology stack.

Dash Platform is a technology stack for developing decentralized applications on the Dash network. The two most important architectural components, Drive and DAPI, transform the Dash P2P network into a document-based cloud that developers can integrate into their decentralized applications. Dash Platform is currently still in the development phase and is not yet in a state that corresponds to mature software.

This is where our master project comes in, with the given goal of designing and conducting a penetration test of Dash Platform. This final report, written by the executing team, provides a detailed insight into the methodology applied during the penetration test and the results obtained. To conduct the penetration test, both methods of static source code analysis were chosen as well as stress testing techniques such as Denial of Service (DoS) attacks. API testing was also carried out through, for example, fuzzing or selecting targeted payloads, and Dash Platform was examined for game-theoretic approaches.

In the course of this project, some potential attack vectors or ambiguities in the functionality of Dash Platform were found, which should be addressed by the development team before the first post-beta release.

We investigate the security of the cryptocurrency Bitcoin and deal with both the security principle of this new type of currency and the associated security risks for end users.

This paper deals with attacks on the payment network itself, such as DoS attacks, Sybil attacks, the 51% attack in its various forms, and game-theoretic attacks, as well as risks for the end user when using Bitcoin in everyday life and problems with their privacy and the risks that a decentralized system entails. A decentralized system is in its nature transparent to all participants, and it can be assumed that governments, intelligence agencies and criminals also try to gain influence here.

The aim of this paper is to find out how Bitcoin compares to traditional centralized payment systems in terms of security and whether new attacks and problems emerge with the decentralization, which could undermine the network or reveal the pseudonymous payment participants.