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Peer Analysis in the Cryptocurrency Networks
Jeřábek, Vladimír ; Grégr, Matěj (referee) ; Veselý, Vladimír (advisor)
The aim of this thesis is to create a tool that will collect relevant information about active nodes in a Bitcoin peer-to-peer network. We are able to collect important data for more detailed analysis by monitoring the behavior of individual nodes on the network . The proposed solution uses unmodified Bitcoin Core client, which connects to all reachable nodes on the network. The platform has modular design, which offers good scaling as well. Created BiNMo tool (Bitcoin Network Monitor) also employs simple visualization of gathered data. The correct functionality of the monitoring platform was verified in the real operation, where it was monitoring Bitcoin network for more than two months. During that time, BiNMon parsed over 12 TiB of network data and stored over 270 GiB of metadata about active nodes. The entire platform can be deployed within a few minutes, thanks to Docker containerization.
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Darkmarket Forensics
Dolejška, Daniel ; Grégr, Matěj (referee) ; Veselý, Vladimír (advisor)
Overlay networks (like Tor or I2P) create a suitable environment for criminality to thrive on the Internet. Dark marketplaces (a.k.a. cryptomarkets) are one such example of criminal activities. They act as an intermediary in the trade of illegal goods and services. This project focuses on forensic analysis of such web services and subsequent extraction of non-trivial information about the realised orders and payments from selected marketplaces. The main goal is to pinpoint the time interval when an order has been completed on selected marketplaces and its following correlation with cryptocurrency blockchains. The implemented program provides fully automated non-stop monitoring of selected cryptomarkets. That, under certain conditions, allows detection of realised purchases, detailed product and vendor monitoring and collection of various meta-data entries. Law enforcement agencies can use acquired data as support evidence regarding the operation of selected cryptomarkets and their vendors. The obtained information can also indicate current trends in products supply and demand.
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Automatizované generování pravidel pro modifikaci hesel s využitím metod strojového učení
Šírová, Lucia ; Veselý, Vladimír (referee) ; Hranický, Radek (advisor)
The success of password cracking using a dictionary attack is limited by the scope and quality of the used dictionary. One way to enhance the success rate of password cracking is to expand the dictionary with password mangling rules. These rules typically reflect human tendencies in password creation, such as appending numbers at the end of the password or capitalizing the first letter. This bachelor’s thesis describes a tool’s design and implementation process that aims to generate these rules by analysis of existing passwords, for example, from datasets obtained during security breaches. This tool enhances existing solutions by providing a choice of four distinct clustering methods. Unlike other rule-generating tools that leverage machine learning, it broadens the generated rules to nineteen unique types. Additionally, the tool offers customizable configurations for rule types and their priorities. Testing results suggest that the tool discussed in this bachelor’s thesis performs comparably or even better than a previously known state-of-the-art solutions.
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Forensic Analysis of Anonymization Principles of Cryptocurrency Networks
Hromada, Denis ; Zavřel, Jan (referee) ; Veselý, Vladimír (advisor)
Při diskusích o kryptoměnách je častým tématem anonymita. Tato práce se věnuje stavebním blokům kryptoměny Bitcoin a jak na ni navazují kryptoměny jako Ethereum a Dash. Dále popisuje, jak a kde se v minulosti i přítomnosti v kryptoměnových sítích ztrácí soukromí a anonymita. Prvně se zaměřuje na anonymitu, respektive její nedostatky v samotném distribuovaném bloko-řetězu. Práce popisuje efekt znovu-využívání adres a shlukovací heuristiku založenou na společných vstupech transakce. Analyzuje je a popisuje nedokonalé aktuální řešení. Dále se práce zaměřuje na anonymitu mimo bloko-řetěz. Tedy na podpůrné služby, které jsou nedílnou součástí funkce kryptoměnových sítí jako jsou kryptoměnové peněženky. Práce diskutuje úschovu klíčů, různé druhy peněženek a jak komunikují s kryptoměnovými sítěmi. Následuje návrh modelu útočníka, jež je schopen odposlouchávat komunikaci uživatele kryptoměnové peněženky. Avšak nedokáže ji měnit. Jsou popsány vlastnosti, schopnosti a očekávaná úskalí takového útočníka. Poté práce věnuje pozornost třem kryptoměnovým peněženkám: Trezor Suite, Ledger Live a Electrum Wallet. Na těchto peněženkách demonstruje výše zmiňované vlastnosti kryptoměnových peněženek v praxi. Na základě všech těchto informací je navržena a implementována aplikace, jež je schopna napomoci uživateli určit, zda zachycený síťový provoz obsahuje komunikaci generovanou kryptoměnovou peněženkou. Nakonec je implementovaná aplikace podrobena testům. Výstupem těchto testů je, že za pomoci implementované aplikace je možné určit, jaká kryptoměnová peněženka byla použita. A to za předpokladu, že zachycený provoz obsahuje komunikaci, jež peněženky generují při jejich prvotním zapnutí. Následuje vyhodnocení práce a její další možné rozšíření.
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Password Leaks Automated Processing
Dvořák, Jakub ; Veselý, Vladimír (referee) ; Pluskal, Jan (advisor)
The aim of this thesis is to find databases of leaked data and to create an application capable of processing the data, storing it in a suitable database and enabling searching of the data on the basis of significant data. Among other things, the work deals with database research and measurement of uploading and data retrieval speeds, in order to select a suitable database used in the final solution. The resulting application is able to detect the encoding of the input file, the data format and stored items. Using the web interface, it also allows data to be searched based on filtering conditions from a database that has 5 157 229 040 records of leaked data at the time of theses submission. The results of this thesis provide a tool for processing and analysing databases of leaked passwords.
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Financial Protocol Simulator
Vymlátil, Martin ; Pluskal, Jan (referee) ; Veselý, Vladimír (advisor)
This paper deals with the creation of a simulator for financial protocols ISO8583 and SPDH.The simulator was designed and implemented in C++ language based on the analysis of the financial protocols. The simulator was tested on pre-prepared authorization messages and was also tested against the real POS terminal. Possible extensions for the simulator were discussed at the end of this thesis.
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VoIP in Jabber Client
Kulička, Vojtěch ; Veselý, Vladimír (referee) ; Mlích, Jozef (advisor)
Práce se zabývá možnostmi implementace VoIP do existujícího XMPP programu se sdílenou tabulí. Analyzuje možnosti využití současných technologií pro podporu VoIP. Cílem je nahrazení stávajících komunikačních knihoven klienta za telepathy. Dále také přidání VoIP.
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Webmail Traffic Reconstruction
Slivka, Miroslav ; Ryšavý, Ondřej (referee) ; Veselý, Vladimír (advisor)
Webmail applications are very popular these days. Besides typical usage, thanks to ciphered communication, they can be used for malicious activity like confidential data loss. This thesis discusses webmail events detection based on common webmail signatures in captured network traffic. Also there will be discussed SSL/TLS interception and decryption for further data analysis. The modules in this thesis are designed and implemented for Netfox.Framework forensics analysis tool. The Netfox project is developed at FIT BUT under security research project SEC6NET.
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Deanonymization Heuristics for Cryptocurrencies
Anton, Matyáš ; Grégr, Matěj (referee) ; Veselý, Vladimír (advisor)
The cryptocurrencies are growing more and more popular, both due to their independency on institutions and the feeling of anonymity they provide. This is, however, also accompanied by an increasing number of their abuse for criminal activities. This thesis explores the principles of current cryptocurrencies as well as techniques used for increasing anonymity of their usage. Based on the findings, it proposes a solution attemping to deanonymise activity in select cryptocurrencies.
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Modelling and Reliability Analysis of Campus Network at the BUT
Kraus, Zdeněk ; Ryšavý, Ondřej (referee) ; Veselý, Vladimír (advisor)
This thesis informs about technologies and architecture of computer network at BUT. It describes chosen technologies and some of theirs variants. Further, it contains simulation model design of a network switch device. That is followed by the model implementation with detailed description of model parts. Then, the model is tested on a set of simulation scenarios and it is evaluated in comparison with theoretical basis and real devices. In conclusion, thesis suggests future model development and improvements.
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