Reverse engineering of hardware IP block is a common practice for competitive purposes in the semiconductor industry. What is done with the information gathered is the deciding legal factor. Once this information gets into the hands of an attacker, it can be used to manufacture exact clones of the hardware device. In an attempt to prevent the illegal copies of the IP block from flooding the market, layout-level obfuscation based on switchable dopant is suggested for the hardware design. This approach can be integrated into the design and manufacturing flow using an obfuscation tool (ObfusTool) to obfuscate the functionality of the IP core. The ObfusTool is developed in a way to be flexible and adapt to different standard cell libraries and designs. It enables easy and accurate evaluation of the area, power and delay v/s obfuscation trades-offs across different design approaches for hardware obfuscation. The ObfusTool is linked to an obfuscation standard cell library which is based on a prototype design created with Obfuscells and 4-input NAND gate. The Obfuscell is a standard cell which is created with switchable functionality based on the assigned dopant configurations. The Obfuscell is combined with other logic gates to form a standard cell library, which can replace any number of existing gates in the IP block without altering it's functionality. A total of 160 different gates are realized using permutated combinations starting with 26 unique gate functions. This design library provide a high level of obfuscation in terms of the number of combinations an adversary has to go through increase to 2 2000 approximately based on the design under consideration. The connectivity of the design has been ignored by previous approaches, which we have addressed in this thesis. The connectivity of a design leaks important information related to inputs and outputs of a gate. We extend the basic idea of dopant-based hardware obfuscation by introducing "dummy wires". The addition of dummy wires not only obfuscates the functionality of the design but also it's connectivity. This greatly reduces the information leakage and complexity of the design increases. To an attacker the whole design appears as one big 'blob'.This also curbs the attempts of brute force attacks. The introduced obfuscation comes at a cost of area and power overhead on an average 5x, which varies across different design libraries.

This master's thesis seeks to design, implement, and point out new techniques for obfuscation of ransomware activity using the entropy principles of data that do not fall within the detection capabilities of known anti-ransomware and anti-virus tools. The proposed techniques are aimed at changing the ransomware activity in the downgrading phase (encryption or obfuscation) of files on the infected system.

Diplomová práca je o bezpečnostnom testovaní obfuskovaných Android aplikácií. Teoretická časť práce opisuje základy obfuskácie a spomína niektoré vybrané obfuskátory. Dopad obfuskácie na penetračné testovanie je taktiež zmienený. Práca navrhuje dynamickú analýzu ako hlavný nástroj pri obchádzaní obfuskácie. Praktická časť práce popisuje ochrany aplikácie v reálnom čase a spôsoby, ako tieto ochrany obísť pomocou dynamickej analýzy. Druhá polovica praktickej časti je venovaná pokročilým technikám obfuskácie a spôsobom ich obídenia.

In this project I deal with basic description of source code obfuscation and size reduction techniques of programming languages. The project is primary aimed on scripting language named JavaScript and involved analysis of free obfuscation tools for this language. In the final stage I have created an application is based on theoretical scope of this project and able to obfuscate JavaScript source codes on different levels.

WordPress is a very widely used content management system that enables users to easier create websites. The popularity of WordPress has made it a prime target for attacks by hackers since a potential vulnerability would affect many targets. Vulnerabilities that can be utilised in an attack are referred to as exploits. Most exploits are only viable for a subset of all the version of the software that they target. The knowledge of which version of a content managements system a website is running is often not explicit or easy to determine. Attackers can potentially exploit a vulnerable website faster if the version is known, since this allows them to search for existing vulnerabilities and exploits, instead of trying to identify a new vulnerability. The purpose of this thesis is to investigate existing and alternate methods for detecting the version of WordPress on websites that are powered by it. The scope is limited to an analysis of existing tools and the suggested methods for version identification are limited to identification using unique values that are calculated from the contents of files. The suggested methods for version identification and the generation of the required data is implemented using Python 3, the programming language. We investigate the feasibility of version obfuscation, how discernible a version of WordPress is, and how to compare versions of WordPress. The thesis has proven the feasibility of version identification with a new perspective that delivers more accurate results than previous methods. Version obfuscation has also been proven to be very feasible without affecting the usability of the WordPress website. Furthermore, a method for discerning between two specific versions of WordPress is presented. All the results are in theory applicable to other software projects that are hosted and developed in the same way. This new area of research has much for security professionals and has room for future improvement.

No description available.

Práce je zaměřena na rozpoznávání specifického chování pomocí generického zpětného překladu. Generický zpětný překlad je proces, který transformuje spustitelné soubory z různých architektur a formátů objektových souborů na stejný jazyk na vysoké úrovni. Tento proces se vztahuje k nástroji Lissom Decompiler. Pro účely rozpoznání chování práce zavádí Language for Decompilation -- LfD. LfD představuje jednoduchý imperativní jazyk, který je vhodný pro srovnávaní. Konkrétní chování je dáno známým spustitelným souborem (např. malware) a rozpoznání se provádí jako najítí poměru podobnosti s jiným neznámým spustitelným souborem. Tento poměr podobnosti je vypočítán nástrojem LfDComparator, který zpracovává dva vstupy v LfD a rozhoduje o jejich podobnosti.

This dissertation studies asymmetric pricing in the small (APIS), where small price increases outnumber small price decreases, the asymmetry disappearing for larger price changes; and the corresponding reversed phenomenon (APIS-R). Current evidence suggests retailers deploy these pricing practices despite menu costs and potential consumer concerns. There is also evidence that inflation is only a partial contributor to the phenomena. These point to possible strategic intent driving these retail pricing practices. However, there are only a few papers in the domain, and none specifically address the cross-sectional and longitudinal variations. Further, existing results are mostly based on a single retailer, limited products, short time span, and legacy datasets dating back to the 1980s and 1990s, leaving their current relevance unsettled. Recent papers also question if small price changes are measurement artifacts. This dissertation addresses these gaps by analyzing several large contemporary datasets – a scanner dataset with more than 79 billion price observations and a matching consumer panel dataset with more than 50,000 participating panelists. Our key results imply the pricing practices can be retailers’ strategic responses to the cognitive tasks faced by consumers. Chapter 1 is a general introduction to the thesis. Chapter 2 sets up the fundamentals of the phenomena and reports robust evidence of APIS and APIS-R across the retail price spectrum. Chapter 3 examines the cross-sectional variations of the phenomena and finds that APIS and APIS-R are associated with product characteristics such as purchase frequency and category price level, as well as retail format such as HILO or EDLP. Chapter 4 explores the longitudinal variations and finds that business cycles are a major time-varying factor influencing retail practices of APIS and APIS-R. Chapter 5 concludes with reflections on the findings, implications for theory and practice, limitations, and suggestions for future studies. / Dissertation / Candidate in Philosophy / This dissertation studies asymmetric pricing in the small (APIS), where small price increases outnumber small price decreases, the asymmetry disappearing for larger price changes; and the corresponding reversed phenomenon (APIS-R). There are only a few papers in the domain, and none explain their cross-sectional and longitudinal variations. Existing results are mostly based on a single retailer, limited products, short time span, and legacy datasets dating back to the 1980s and 1990s, leaving their current relevance unsettled. Recent papers also question if small price changes are measurement artifacts. This dissertation addresses these gaps by analyzing several large contemporary datasets. The research finds robust evidence of both APIS and APIS-R in the retail price spectrum, and provides explanations for their cross-sectional variation, across products and retailers, as well as longitudinal variations, across business cycles. The results indicate the pricing practices can be retailers’ strategic responses to the cognitive tasks faced by consumers.

Embedded Internet of Things (IoT) products are taking up a larger part of the market thanks to smaller, cheaper and more advanced components. For companies that spend time and resources on developing software for these products, it is important to keep that software secure to maintain the advantage gained. This can be done in multiple ways, each with its own advantages and disadvantages. One way is by utilizing code obfuscation to make the software more difficult to understand and therefore harder to reverse engineer. However, changing the code comes at a cost, this thesis aims to find out what that cost is. This is done by comparing two versions of code: the original code and its obfuscated version. These versions were compared with respect to execution time and readability. The results of the tests indicate a small increase in execution time for the obfuscated version, but it also showed a big increase in how difficult it was to read. This means that obfuscating code will have a small performance penalty, but is much more resilient to reverse engineering. It is also important no note that manually obfuscating code is not practical for a production environment, since a large part of the development time will be spent on obfuscating the code instead of improving it. Therefore, it is important to have an automated obfuscation tool. / Inbyggda IoT produkter tar upp en större del av marknaden tackvare billigare, mindre och mer avancerade komponenter. För företagen som spenderar tid och resurser på att utveckla mjukvara till dessa produkter är det viktikgt att hålla den mjukvaran säker. Detta kan göras på många olika sätt, varje med sina fördelar och nackdelar. Ett sätt är att använda kodobfuskering för att göra mjukvaran svårare att förstå och darmed svårare att baklängeskonstruera (reverse engineer). Men, att ändra koden kommer med ett pris, denna uppsats försöker hitta vad den kostnaden är. Detta görs genom att gämföra två versioner av kod: orginalet och en obfuskerad version av den. Dessa versioner gämförs sedan på exekveringstid och lasbarhet. Resultatet av testet visar en liten ökning i exekveringstid för den obfuskerade versionen, men en stor ökning i hur svår den är att förstå. Detta betyder att obfuskerad kod kommer ha en lite sämre prestanda, men är mycket med tålig för baklängeskonstruktion (reverse engineering). Det är också viktigt att påpeka att manuell kod obfuskering inte är praktiskt för en produktionsmiljö, då mycket tid kommer läggas på att obfuskera koden istället för att förbättra den. Därför är det viktigt att ha ett aotumatisk obfuskerings verktyg.

No description available.