Ing. Michal Štepanovský, Ph.D.

Ing. Michal Štepanovský, Ph.D.

Ing. Jiří Dostál, Ph.D.

Department of Computer Systems

The aim of this thesis is to test the feasibility of Fallout exploit which targets vulnerability of processor architectures and belongs to a group of exploits known as MDS. Its theoretical part identifies the prerequisites necessary to successfully use this exploit and subsequently analyses its feasibility and impact. A program designed to detect weak spots in operating systems and processor architecture was coded as a part of the implemenation part of the thesis. Its purpose is to verify if incorrect data can be forwarded to processing without prior check or alternatively if the process should have access to the data in question. The included program does not utilize any TSX instructions and hence can be used on processors which do not support this extension.

Thesis on DSpace

Ing. Michal Štepanovský, Ph.D.

Ing. Jiří Kašpar

Department of Computer Systems

This bachelor's thesis is dedicated to research of select security vulnerabilities in modern processors. The theoretical portion contains a summary of the Rogue In-Flight Data Load, Load Value Injection and Foreshadow vulnerabilities. A more comprehensive description of the Lazy FP State Restore vulnerability is given including theoretical attack concepts. I present an attempt at implementing this attack which aims to leak a limited amount of another program's private data stored in CPU registers. I describe portions of the implementation source code which form the fundamentals of the attack. Findings made while creating the implementation and analysis of the prerequisites of this attack lead to the conclusion that LazyFP is not a severe security threat at this time.

Thesis on DSpace

Ing. Michal Štepanovský, Ph.D.

Ing. Zdeněk Buk, Ph.D.

Department of Theoretical Computer Science

Goal of this work is to implement a processor simulator with MIPS32 instruction set. I will implement this as two programs - a simulator core written in Verilog hardware definition language and a GUI application written in Java with usage of graphic framework JavaFX. Result of this work is an application that reads and runs a program written in MIPS32 machine code and shows history of the program run. It displays values in processor modules and wires, data memory, instruction memory and cache simulation. This simulator will be used in BI-APS (Architectures of Computer Systems) course, instruction set is modified for needs of this course.

Thesis on DSpace

Ing. Michal Štepanovský, Ph.D.

Ing. Jitka Hrabáková, Ph.D.

Department of Applied Mathematics

Age at death estimation is one of the main tasks when creating biological profile in forensic anthropology. Skeletal remains are used for the estimation. Acetabulum is currently at the forefront of research interest. This thesis focuses on age at death estimation from acetabulum images using convolutional neural networks. In addition, emphasis is placed on input data preprocessing and hyperparameters tuning of selected model. The result of this thesis is a regression machine learning model for age at death estimation using acetabulum scans.

Thesis on DSpace

Ing. Michal Štepanovský, Ph.D.

Ing. Jiří Kašpar

Department of Theoretical Computer Science

This thesis deals with analysis, design and implementation of a system which allows to simulate running programs for target microarchitecture. Research part of the thesis deals with comparing of existing solutions and describes technologies and terms used further in the thesis, the practical part follows the presentation of the program design, description of its parts and methods used during implementation. The chosen problem was solved by integration of the program with hardware simulator Icarus Verilog. There was created a system which supports simplified microarchitecture MIPS32 in the base with the possibility to configure further microarchitectures. The benefit of this thesis is that students of computer-driven subjects will understand the structure and operation of processors thanks to visualisation. In attachment on USB stick there is a program, source codes and a manual.

Thesis on DSpace

Ing. Michal Štepanovský, Ph.D.

Department of Software Engineering

This bachelor thesis describes the process of development of a software application used to estimate the age of an adult based on a scan of his pelvis bone. Machine learning algorithms are currently being widely used in various fields including in forensic anthropology, paleontology and history. Using this software will make their part of the job focusing on age estimation significantly easier. In this thesis I focus on the analysis of input data, design of multiple machine learning models, which are used to estimate the age of individuals, their subsequent validation and lastly on the implementation and testing of the user interface.

Thesis on DSpace

Ing. Michal Štepanovský, Ph.D.

doc. RNDr. Ing. Petr Zemánek, CSc.

Department of Computer Systems

This thesis focuses on Linux kernel vulnerability CVE-2019-9213, which relates with a bug on Memory Management subsystem on Linux operating system. It allows mapping of vitual address 0. This vulnerability with Mutagen Astronomy and Dirty COW are analyzed and an attack is design in order to gain privilege escalation. On address 0 is stored a malicious code and is run in privileged mode. The attack is successfull however some system's protections are disabled.

Thesis on DSpace

Ing. Michal Štepanovský, Ph.D.

Ing. Jiří Buček, Ph.D.

Department of Computer Systems

The goal of this thesis is to describe a principle of the ZombieLoad attack and to perform it. The theoretical part introduces some specifics of modern processors. After that follows an analysis of the attack which includes a description of a cache side-channel. The theoretical part concludes with a chapter describing mitigations applied by operating systems and processors. The practical part describes the implementation of five variants of the attack on the Linux operating system. The description also includes any obstacles that can be encountered during an attack attempt and their solutions. The last chapter analyses the success rate of the implemented variants and abusement of vulnerabilities.

Thesis on DSpace

Ing. Michal Štepanovský, Ph.D.

RNDr. Ing. Vladimír Smotlacha, Ph.D.

Department of Computer Systems

The main content of this bachelor thesis is the study of problems of elastic optical networks and their theoretical solutions. The optical fibers as a whole, their distribution and their properties are presented here. In my work I also focus on the comparison of elastic optical networks with dense wave multiplexing "DWDM". This comparison part is to find out what volume of spectrum and under what conditions newer technology can save. The contribution of the work is also a detailed presentation of the RSA problem, which discusses the main functions of optical fibers, namely routing and spectrum allocation. However, there are many problems associated with this, such as spectrum fragmentation, signal modulation and others, which are also presented in this work. At the end of the work I deal in more detail with the problem of error resistance, which I analyzed in detail.

Thesis on DSpace

Ing. Michal Štepanovský, Ph.D.

doc. Ing. Ivan Šimeček, Ph.D.

Department of Digital Design

This thesis aims to explain the superscalar processor's working principles and to design a microarchitecture based on the RISC-V RV32I instruction set architecture. The designed microarchitecture is called VTM (Veznik Tomas Microarchitecture) and is described using SystemVerilog hardware description language. The VTM is a dual-issue out-of-order superscalar microarchitecture that executes up to four instructions in the execution stage simultaneously. The primary output of this thesis is the VTM source code. The simulation, accompanied by the theoretical part of this thesis, serves as a learning tool for anyone who wants to understand the inner workings of superscalar processors, with students as the primary audience.

Thesis on DSpace

Ing. Michal Štepanovský, Ph.D.

Ing. Josef Kokeš

Department of Computer Systems

This thesis focuses on the steganography, specificaly hiding any data into the provided image, using error-correcting codes. The thesis analyzes the methods of hiding data, various types of error-correcting codes and their capabilities to extract the hidden data from the damaged (or modified) image. Based on this, an application for hidding the given data into the image is created, including a user interface. This application allows to select the error-correcting code and embedding method to be used. With the help of created application, the error-correcting codes and embedding methods are practicaly analysed. The application was created and tested for the GNU/Linux operating system.

Thesis on DSpace