This master’s thesis focuses on implementation of ABC (Anonymous attribute-based credential) pilot system on the Android platform. The support for attribute authentication on the Android platform is very weak in terms of the number of implementations and needs a special attention. The theoretical part of the thesis describes the cryptographic support on the Android platform, the use of the Android Native Development Kit (NDK) and the Host-Card Emulation (HCE) service. The theoretical part of the thesis also includes a description of attribute authentication schemes, including a pilot RKVAC system. The practical part describes the implementation of the RKVAC system on the Android platform along with the implementation of a custom cryptographic kernel based on the native MCL cryptographic library. The practical part of this thesis describes implementation proces of RKVAC system on Android plaform, that uses native cryptographic library MCL. The final part shows the results of time, memory and computation difficulty of developed applications.

The thesis deals with design and implementation of prototype of mobile application for Android and iOS operating systems. Framework React Native was chosen for realization because it allows multiplatform development. Application focuses on data visualization from sales of handmade products on Fler web portal.

Cílem této práce je vylepšit implementaci modulu pro mobilní aplikace pro výuku výslovnosti, najít místa vhodná pro optimalizaci a provést optimalizaci s cílem zvýšit přesnost, snížit čas zpracování a snížit paměťovou náročnost zpracování.

Digitalization is happening all around us as more tasks get software assistance, to ease the workload and improve performance. This opens up for endless possibilities but it also comes with challenges. The progress made within software development means that the first solutions implemented can differ a lot compared to the latest for a company. This spread makes maintenance significantly harder due to having different implementations or even different operating systems. Cross platform compatibility is a technique that battles this spread by allowing for a single implementation to be used in all environments, enabling maintenance to be focused solely on one product. The transitioning towards cross platform applications is easy when there is no  external hardware involved. However when there is external hardware the transitioning needs to take limitations regarding hardware compatibility into consideration, which has been the case for this project. In the thesis, a proof of concept has been developed for migration from native Android towards React Native which allows for a cross platform compatible application. External hardware in the form of a card reader, receipt printer and touch screen are included to analyze the possibility to migrate without having to replace the current hardware due to limitations regarding hardware accessibility and performance. This work shows that it would be possible to transition from a native Android application with external hardware to a React Native application if an additional backend environment is implemented alongside. The backend is for validation and token generation towards third party programs connected to the hardware. This proof of concept shows that the performance loss is within an acceptable boundary which only marginally affects user experience.

The recent growing popularity of mobile devices has led to the establishment of several popular mobile platforms such as the Android operating system. To foster growth in this evolving market, Application Programming Interfaces (APIs) were created to enable developers to create mobile device applications that utilize mobile device features and functionality for personal or widespread commercial use. However, as a result of excessive device and API evolution, mobile development faces increasingly complex issues, including an alarmingly rapid decay of development resources. This thesis conducts a case study around one such resource: a series of Android app development lab exercises used in an Android app development course taught at California Polytechnic State University, San Luis Obispo. First, these labs and their respective written guides were modernized and fitted for backwards-compatibility to better reflect newer Android devices and development tools at the time. The updated labs were subsequently used in the next course offering, with student lab feedback recorded for evaluation. Several years later, the apps from these new labs were further tested for abnormal behavior on a variety of Android devices. Results from analyzing all feedback and observations show that despite all measures taken to future-proof these labs, Android device and API evolution continues to vastly outpace third-party Android resources without frequent modernization and upgrades.

Thesis describes worldwide operating systems for smart phones with focus on third party application development possibility. Also describes touch control and writing using the virtual keyboard of smartphones. The second part describes the analysis and projection of virtual keyboard with emphasis on ergonomic use for handicapped person. One solution is selected and programmed for operating system Android. Thesis contains complete procedure of application developing, starting with first request, through designing, programming and ending with debugging, testing and release application on Android Market.

The diploma thesis solves the problem of design and implementation of library for digital signal processing on Android platform. It describes problems with development software on this platform. There is also a debate about portion of Android on market. It describes technologies and ways, that were used for developing an application. It also explains the efficient programming techniques, in some cases, offering alternative solutions and ways. Effectiveness examines from the perspective of processing power and memory consumption. Continues through analysis Android platform architecture, and some features of its system to the description of some of its parts. Gets up to the description of work with the audio data formats, or to work with files and various collections of data. Then description continues with functions and the application itself. The actual library is controlled through the user interface and some other functions. User select parameters of each signal to be processed. The signal can be generated or the recorded sound signal. After selecting the parameters of each filter, the user can play the output signal and observe the change. In other part different instruments are compared and discussed some improvements, which accelerate and improve the entire application. The conclusion summarizes the results and benefits of the entire diploma thesis.

The goal of the master’s thesis was to propose two laboratory exercises, integrating newly purchased devices HTC Desire and Nokia N900. Designed tasks bring new technologies and services to education process. The first task examines the configuration of branch exchange Asterisk PBX and analyzes SIP protocol. Part of exercise is concentrated on high-speed data transmission in mobile and wireless networks, regarding to usability of VoIP technology. The second exercise introduces to vulnerability of VoIP technology. It contains simulations of attacks on branch exchange Asterisk, DoS attack and discusses methods to secure VoiP communication. The part of this exercise examines usage of HTC Desire phone, instead of ordinary Wi-Fi access point.

The aim of this master’s thesis is design and implementation local chat system for mobile devices and smartphones. System contains main server, witch covers communication with application for smartphones and web server, witch covers communications with browsers and presentation application, witch goal is to presenting chat to area. Smartphone ap- plication is crated for Android, iOS, Windows Mobile and Symbian operating systems. Wifi network is used for communication and message sending and signal coverage area defines local chat. Messages are shown dynamically and it’s possible send them as user status to Facebook social network.

The aim of this diploma thesis was to created application for detection and decoding QR codes using devices with the Android Operating System. For preprocessing of the visual field camera is used OpenCV library. Designed preprocessing string searches a perspective transforms possible QR codes. This is suppressed a shape distortion QR code that would otherwise reduce the successful decoding. At the same time the preprocessing string applied unsharp mask, which reduces the effect of motion blur image caused by the camera motion. Thus preprocessing scene is finally decoded using ZXing library. Described manner it is possible to achieve a higher success rate detection and decoding of QR codes than other conventional QR readers.