The goal of this thesis is to analyze the technologies for distributed computing in password cracking. Distribution is a key factor regarding the total time of cracking the password which can sometimes take up to tens of years. In the introductory section we take a look at the general password cracking, types of attacks and the most popular tools. Next we address the GPU parallelization as well as the need of distributed computing on multiple computers. We look at all kinds of technologies, such as VirtualCL, BOINC, MPI and analyze their usability in password cracking. We examine each technology's performance, efficiency, scalability and adaptability when given pre-defined conditions. Part of this thesis is a design and implementation of distributed password cracking using MPI technology along with Hashcat, a self-proclaimed World's fastest password cracker.

This thesis describes passwords cracking using probabilistic context-free grammars, specifically PCFG Cracker tool. The aim of the thesis is to design and implement enhancements to this tool, which reduce the size of output dictionaries while maintaining acceptable success rate. This work also solves critical parts in the tool that slow down the overall duration of the program. Another goal of the thesis is to analyze and implement targeted attack dictionaries that increase the scope and success rate of generated passwords.

The PRINCE algorithm is a faster and more advanced version of a combination attack. Non-distributed password breaking often encounters its limits, and its applicability to real tasks decreases due to the increasing demand for computing resources of the device. The aim of this work is to design a distributed version of the the PRINCE attack as an extension of Fitcrack system, which focuses on distributed password cracking. The proposed design is implemented and integrated into the Fitcrack system. The work examines the PRINCE attack on a set of experiments, which examines the impact of various configuration options. Part of the experimental part is a comparison of the PRINCE attack with the dictionary and combination attack. The purpose of the comparison is to find cases where the PRINCE attack is better than other attacks. Finally, the integrated PRINCE attack solution in the Fitcrack system is compared with the solution implemented in the Hashtopolis system.