Keywords: 5G, OpenAirInterface, URRLC, Edge Computing, MEC, Robotics, ROS
Astract: The novel mobile telecommunications standard 5G offers many improvements compared to its predecessor 4G. While from an end consumer perspective, the increase in bandwidth and download speed are the most crucial, the 5G use case Ultra-Reliable Low Latency Communications (URLLC) is the most important for the Internet of Things (IoT). The IoT consists of connected devices and sensors that exchange data with each other and central nodes. Often, the communication between the sensors and a central node must not exceed a low latency, e.g., 10ms. While URLLC reduces the latency in 5G, the link to a distant central node may introduce substantial latencies. A solution to solve this issue is to physically move the central node as close as possible to the connected 5G device. This is the main concept behind edge computing in 5G. As a mobile robot can be classified as one or more "things" in the IoT, it has similar requirements. For example, when a robot is localizing itself in a known or unknown environment, it relies on Light Detection and Ranging (LIDAR) scans to map the world. This procedure is called Simultaneous Localization and Mapping (SLAM). It is crucial that the measurements from the LIDAR sensor are processed with low latency, as delays can compromise the accuracy of the localization. However, Simultaneous Localization and Mapping (SLAM) is also computationally expensive. Therefore, it is highly desired and sometimes required to offload this computation to another computer, as robots are often hardware-constrained.The underlying hypothesis of this work is that it is possible to offload a SLAM algorithm to the edge of a 5G network without compromising functionality and quality of the localization. To achieve this, existing approaches to edge computing in 5G are analyzed and compared. Further, the open source 5G implementation OpenAirInterface is adapted to support the edge computing use case, which has not been considered in its initial design. Finally, an experiment is conducted which compares the accuracy and functionality of the SLAM algorithm in three different deployments: Local, WiFi and 5G edge. The results of this thesis show that offloading SLAM to the 5G edge is possible, whereas the accuracy and functionality of the localization and the produced map are slightly lower compared to the WiFi deployment. While much can still be optimized, this work lays the foundation for 5G-enabled mobile robotics, fully operated with open source software.

Keywords: Arm TrustZone, rootkit, reverse engineering, memory manipulation
Astract: Mobile devices such as smartphones carry an increased amount of personal and confidential data. In order to protect sensitive services from malware, the Arm TrustZone logically divides the device into two so-called “worlds”. Critical services are running in an isolated execution environment called “secure world” which has its own operating system (OS). The regular OS and its applications are located in the “normal world” and can use services provided by the secure world. While the secure world memory is protected from the normal world, the secure world has full access to the normal world memory. Implementations of the Arm TrustZone are specific to the vendor and proprietary on currently relevant consumer devices. At the same time, security vulnerabilities have been discovered in all major implementations. Summarizing, the Arm TrustZone is isolated, proprietary, privileged, vulnerable and widespread. These properties are perfect preconditions for hosting advanced malware such as rootkits. Usage of the Arm TrustZone as an environment for rootkits has been suggested already back in 2013. Since then, no publications or implementations of rootkits utilizing the Arm TrustZone were presented to the best of our knowledge. Major challenge for a secure world rootkit is that there is no semantic interpretation of the normal world memory available. Reverse engineering of kernel data structures at runtime is required to implement rootkit features. Invariants are used to reconstruct compilation-dependent or randomized symbol addresses. This work makes the following contributions. 1) Design of a rootkit architecture utilizing the secure world. 2) Proof-of-concept implementation of rootkit functions supporting multiple recent Linux kernel versions as normal world OS and circumventing basic protection mechanisms. 3) Discussion of defensive techniques protecting the normal world from malware running in the secure world. Reconstructing the internal structures of the kernel depends on the underlying implementation. Linux is an actively developed project, thus kernel structures potentially change over time. Minor changes in the source code are compensated by the rootkit implementation. Stability of the developed rootkit is proven experimentally by testing it on various versions of the Linux kernel.

Keywords: TPM 2.0, Rootkits, Secure Boot, Measured Boot, Linux boot process
Astract: Rootkits are a kind of malware that compromise components lower than the operating system for example the kernel, bootloader and BIOS. Rootkits pose a major threat to computer security as they operate with elevated privileges and are often hard to detect from the operating system level. A computer system requires a secure basis and a chain of trust on all levels up to the operating system to increase safety. To achieve this every component of the boot process is measured before being loaded and executed, this method is also known as measured boot. Secure Boot on the other side executes only components with a valid signature or a valid hash. The Trusted Platform Module (TPM) is a cryptographic microcontroller located on the computer’s motherboard. It securely stores the measurements of the boot process and can attest to the component’s integrity. This also means that not only users but also remote entities can check the system state. The TPM is a passive module which is called by other components and software. This thesis describes a concept to prevent the execution of rootkits on Linux-based desktop systems through a boot process with TPM 2.0. The concept is a combination of a secure and measured boot in which updating of components should not break the attestation or the trustworthiness of the system.

Keywords: security test concept optimisation, test suite reduction, test case automation, test case prioritisation, e-health
Astract: IT systems are part of many business models in todays business world. With the question of security of these systems, IT security becomes a concern of growing importance. The need for extensive security testing is a logical consequence, especially when it comes to the domains of eGovernment and e-health, where highly sensitive data is handled. It is every service providers responsibility to implement adequate security measures for the datas safety. With new data protection laws, e.g. the EU-wide general data protection laws, regulations regarding the processing and storage of sensitive data, like health data,became stricter and penalties for improper securing of the systems that handle such data are significant and can cause serious economic damage.This results in the need for security testing. As the security of a system cannot be proven, as stated by Geer[34], but only its insecurity, this bears the necessity for constraints to provide efficient test execution. These constraints ensure that budget limits are not exceeded whilst maintaining sufficient test coverage.This work analyses how a security test concept can be optimised for economic efficiency, taking into account the state-of-the-art and best practices in security testing, test suite reduction, test case automation, and test case prioritisation. The result is an optimisation method, which can help to optimise security test concepts. The method was tested on a real-world example a complex system with very high protection needs in the field of e-health.

Keywords: Android Application Security, Automated Security Classification, Google Play Store Security Evaluation, TaaS, Microservice based Framework, OWASP Mobile Top 10, CMU-Rules
Astract: The operating system Android is with almost 85% market share worldwide in a leading position and the Android Google Play Store counts around 2.8 million mobile applications. However, the threats these applications involve remain often untold. In the last few years publications and tools with a focus on security areas such as communication, cryptography and data access or data storage have been published. To compose the functionality of different analysis tools and to accomplish an automated security classification of Android applications with a focus on IT-Security, a web-based Testing as a Service (TaaS) framework has been implemented, which integrates various existing security analysis tools. Based on the analysis results of the integrated tools and the recommendations of the Open Web Application Security Project (OWASP) Top 10 as well as the rules of the CERT Department of the Software Engineering Institute of Carnegie Mellon University (CMU) the framework identifies the security class of the analyzed applications. In order to identify the most common security threats and issues, the most secure and vulnerable Google Play Store categories as well as the changes in the security field of cryptography in the last six years, an evaluation was conducted as part of the thesis to automatically determine the security of 100 android applications from 58 different Google Play Store categories that include categories such as Android Wear, Business or Finance. Analyzing the 5.800 Google Play Store applications using the framework attached tools, as well as the security classification of the defined categories Insufficient Attack Protection, Security Invalidation, Access Control, Sensitive Data Leakage and Input Validation resulted in at least one security issue in about 76% of the evaluated applications. The result of critical or insecure classified applications varied in different Google Play Store categories, with lower rates of critical applications found in security-critical categories such as Business, Family Education, Finance and Medical. Most of the issues were located in the Security Invalidation category or more precisely in the areas of Certificate Validation and Cryptography. In the field of Cryptography rules concerning the usage of Electronic Code Book Mode (ECB), Cipher Block Chaining Mode (CBC) with non-random Initialization Vector (IV) as well as static seeds have been evaluated and resulted overall in a decline of problems in the past six years.