P2P Networks Blocking

Tato bakalářská práce se zabývá filtrováním P2P sítí určených k výměně dat. Popisuje vrstvy ISO/OSI modelu, na kterých je možné tyto sítě blokovat. Popisuje nástroje detekující P2P sítě na základě datové části paketu určeného pro operační systémy Linux. Testování dokazuje úspěšnost blokování L7-filtrem a IPP2P filtrem.This bachelor's thesis deals with filtering P2P networks intend for changing data. My work describes layers of ISO/OSI model, which is able to blocking these networks. For Linux describes tools of detecting P2P networks with the aid of data part of packet. Testing proves success of blocking by L7- filter and IPP2P filter.

Implementation of cryptographic primitives

Tato semestrální práce je zaměřena na kryptografické metody. Část se věnuje blokovým šifrám, kde popisuje algoritmy Blowfish a 3DES. Dále se zabývá hashovacími funkcemi, z nich podrobně rozebírá algoritmy SHA-3 a Tiger.This semestral thesis is focused on cryptographic methods. Part of it deals with block ciphers, where are described algorithms of Blowfish and 3DES. It also deals with hash functions of which are analysed algorithms of SHA-3 and Tiger in detail.

A blockchain-based distributed paradigm to secure localization services

In recent decades, modern societies are experiencing an increasing adoption of interconnected smart devices. This revolution involves not only canonical devices such as smartphones and tablets, but also simple objects like light bulbs. Named the Internet of Things (IoT), this ever-growing scenario offers enormous opportunities in many areas of modern society, especially if joined by other emerging technologies such as, for example, the blockchain. Indeed, the latter allows users to certify transactions publicly, without relying on central authorities or intermediaries. This work aims to exploit the scenario above by proposing a novel blockchain-based distributed paradigm to secure localization services, here named the Internet of Entities (IoE). It represents a mechanism for the reliable localization of people and things, and it exploits the increasing number of existing wireless devices and blockchain-based distributed ledger technologies. Moreover, unlike most of the canonical localization approaches, it is strongly oriented towards the protection of the users’ privacy. Finally, its implementation requires minimal efforts since it employs the existing infrastructures and devices, thus giving life to a new and wide data environment, exploitable in many domains, such as e-health, smart cities, and smart mobility

Deduplication file systems

In this thesis the area of data deduplication is presented. Basic concepts of data deduplication are explained along with the main engineering challenges faced when designing or using deduplication systems. The main emphasis is on storage-media data deduplication, i.e., data deduplication at filesystem level. A few existing and very different deduplication filesystems are presented and compared. Special focus is given to Unix filesystems and development of userspace deduplication filesystems -- in this thesis such a filesystem is designed and implemented. The implemented filesystem is conceptually and experimentally compared to the opensource deduplication filesystem lessfs. Architectural decisions of both filesystems are discussed

D.STVL.9 - Ongoing Research Areas in Symmetric Cryptography

This report gives a brief summary of some of the research trends in symmetric cryptography at the time of writing (2008). The following aspects of symmetric cryptography are investigated in this report: • the status of work with regards to different types of symmetric algorithms, including block ciphers, stream ciphers, hash functions and MAC algorithms (Section 1); • the algebraic attacks on symmetric primitives (Section 2); • the design criteria for symmetric ciphers (Section 3); • the provable properties of symmetric primitives (Section 4); • the major industrial needs in the area of symmetric cryptography (Section 5)

Cryptanalysis of the Tiger hash function

Tiger is a cryptographic hash function with a 192-bit hash value. It was proposed by Anderson and Biham in 1996. Recently, weaknesses have been shown in round-reduced variants of the Tiger hash function. First, at FSE 2006, Kelsey and Lucks presented a collision attack on Tiger reduced to 16 and 17 (out of 24) rounds with a complexity of about 244 and a pseudo-near-collision for Tiger reduced to 20 rounds. Later, Mendel et al. extended this attack to a collision attack on Tiger reduced to 19 rounds with a complexity of about 2 62. Furthermore, they show a pseudo-near-collision for Tiger reduced to 22 rounds with a complexity of about 244. No attack is known for the full Tiger hash function. In this article, we show a pseudo-near-collision for the full Tiger hash function with a complexity of about 247 hash computations and a pseudocollision (free-start-collision) for Tiger reduced to 23 rounds with the same complexity. © International Association for Cryptology Research 2007.status: publishe