Wyniki 1-6 spośród 6 dla zapytania: authorDesc:"Bartosz Czaplewski"

A fair distribution scheme for joint fingerprinting and decryption methods DOI:10.15199/59.2016.7.5

  The paper addresses the fairness of the security provided by digital fingerprinting methods. It was noted that the digital fingerprinting techniques are designed primarily to protect service providers against the actions of malicious users, while honest users remain vulnerable to acts of malicious providers. The paper describes the customer’s rights problem and the unbinding problem, which also apply to joint fingerprinting and decryption methods. The author proposes a solution to these problems in the form of fair distribution scheme for joint fingerprinting and decryption methods. The proposed scheme is fair, because it provides the expected protection from the perspective of both the provider and the customer. Mutual authentication is realized using certificates and digital signatures. The scheme does not require that the customer contact with any other party than the seller and, simultaneously, does not require cooperation with the customer during the identification of malicious users. Key words: digital fingerprinting; joint fingerprinting and decryption; customer’s rights problem; unbinding problem; key distribution.1. INTRODUCTION Nowadays, digital multimedia have such a high value that it must be protected in an appropriate way. Illegal copying and redistribution of digital media leads to copyright infringement. This problem causes both financial and moral loss to the authors and their publishers every day. The identification of malicious users is called traitor tracing [1, 2, 3]. In order to solve this problem, digital fingerprinting methods are used. In digital fingerprinting methods, unique authenticating sequences are embedded in the multimedia content. These sequences, called fingerprints, are embedded in an imperceptible manner and therefore all fingerprinted copies on the multimedia content are visually identical. In the case of illegal distribution of a fingerprinted copy by malicious user, it is pos[...]


  A COMPARISON OF THE NEW JOINT FINGERPRINTING AND DECRYPTION FOR SECURING COLOR IMAGES Streszczenie: W artykule porównano nowe metody łącznego fingerprintingu i deszyfracji JFD (ang. Joint Fingerprinting and Decryption) dla obrazów kolorowych zaproponowane w rozprawie doktorskiej dr inż. Bartosza Czaplewskiego. Metody porównano z innymi metodami JFD znanymi z literatury. Metody zostały porównane w kontekście niezauważalności fingerprintów, odporności na szum, odporności na kompresję, odporności na ataki zmowy, oraz odporności na ataki zmowy połączone z kompresją. Abstract: The article compares the new joint fingerprinting and decryption methods for color images proposed in the doctoral dissertation of Bartosz Czaplewski, Ph.D. Eng. The methods were compared to other JFD methods from the literature. The methods were compared in the context of imperceptibility of fingerprints, resistance to noise, resistance to compression, resistance to collusion attacks, and resistance to collusion attacks with compression. Słowa kluczowe: ataki zmowy, cyfrowy odcisk palca, łączny fingerprinting i deszyfracja, multimedia Keywords: collusion attacks, digital fingerprinting, joint fingerprinting and decryption, multimedia 1. WSTĘP Problemem badawczym jest przeciwdziałanie zjawisku nielegalnego rozpowszechniania multimediów. Znane są rozwiązania wykorzystujące techniki cyfrowego odcisku palca (ang. digital fingerprinting), polegające na osadzaniu ukrytych danych w multimediach, których obecność ma służyć identyfikacji piratów. W ostatnich latach powstały metody łącznego fingerprintingu i deszyfracji JFD (ang. Joint Fingerprinting and Decryption), które charakteryzują się minimalnym zapotrzebowaniem na zasoby sieciowe i obliczeniowe. Jednakże, dotychczasowe metody JFD posiadają istotne wady, np. brak odporności na ataki zmowy lub brak odporność na kompresję. Większość rozwiązań zostało zaprojektowanych dla obrazów w odcieniach szarości, a i[...]

Current trends in the field of steganalysis and guidelines for constructions of new steganalysis schemes DOI:10.15199/59.2017.10.3

  1. Introduction Steganography is a field of science of concealing communications by hiding secret messages within other data, e.g. images. At the sender side, the aim of steganography scheme is to embed a secret message into innocent-looking image called cover image. An image containing hidden message is called stego image and is usually transmitted through public channel. At the receiver side, the aim of steganography scheme is to extract the hidden message from the received stego image. Thus, a steganography scheme includes two parts: the embedding algorithm and the extraction algorithm. There are three steganographic architectures [1]: steganography by cover selection, steganography by cover synthesis and steganography by cover modification. In steganography by cover selection, the sender communicates the secret message by choosing a cover image that has hidden meaning. In steganography by cover synthesis, the sender creates his own cover image which carry the secret message. In steganography by cover modification, the sender introduces modifications to a cover image in order to hide the secret message. This article concerns the steganography by cover modification. Steganalysis is a field of science of detecting secret communications carried by steganography schemes. The aim of steganalysis is to detect the presence of a hidden message in test image by distinguishing between stego and cover images. If a stego image is detected then the secret communication is revealed and the steganography scheme is broken. It is not necessary to discover the content of the secret message to break the steganography scheme, since determining the presence of the message is sufficient. Steganalysis schemes are the focus of this article.There are three steganalysis scenarios [1]: passive steganalysis, active steganalysis, and malicious steganalysis. In passive steganalysis, the communication is observed and analyzed, but not interfered, in o[...]


  The proposed method is a new Joint Fingerprinting and Decryption (JFD) method that uses a cipher based on quaternion rotation to encrypt color images that are then sent to all users via multicast transmission. Individual decryption keys depend on the users’ fingerprints, so that a unique fingerprint is introduced into the image during decryption for each decryption key. A simulation-based research was conducted to examine the method’s robustness against collusion attacks. 1. INTRODUCTION This paper addresses the problem of unauthorized redistribution of multimedia content by malicious users (pirates). There are two ways to protect distributed multimedia: encryption and digital fingerprinting [1]. The goal of encryption is to ensure that only authorized users with proper decryption keys are able to use distributed multimedia. However, after decryption the data loses its protection and may be illegally redistributed by malicious users. In order to maintain security after decryption it is necessary to use a digital fingerprint. Digital fingerprinting is a data hiding technique in which data is protected by unique sequences, called fingerprints. Each fingerprint identifies an individual user and is embedded in the image in such a way that it is imperceptible to the human eye. If a pirate redistributes his or her copy, the analysis of the embedded fingerprint should allow to identify the pirate. Joint Fingerprinting and Decryption (JFD) [2,3,4,5] methods combine encryption and fingerprinting through embedding fingerprints during decryption process. The distribution side encrypts multimedia by using the encryption key and then sends the encrypted data via multicast transmission. Each user has a unique decryption key which is different from the encryption key and introduces some minor changes into decrypted images. These changes are imperceptible to the human eye and are unique for each user, hence they are the us[...]


  Events Visualization Post is part of the STRADAR project [1], which is dedicated to streaming real-time data in distributed dispatcher and teleinformation systems of the Border Guard (BG). The project is implemented for the security and defense and it is funded by the National Centre for Research and Development. The project is the extension of the KONSOLA project [2,3]. The STRADAR project consists of multiple stationary and mobile elements [1], although the most significant are the Center Server (CS), the Archival server (AS) and the Events Visualization Post (EVP) [4]. The CS runs the custom Map Server (MS) application, manages the list of visualization tasks, and performs various management operations. The MS provides access to data on naval situation for visualization on digital maps. The AS provides access to archived data, which can be of various types: files, images, SMS, SDS, video, or audio. Finally, the EVP enables interactive visualization of data, generation of new visualization tasks, and some minor control functions. The Events Visualization Post is a software designed for simultaneous visualization of data of different types in BG headquarters which operates on a PC with a very high resolution multi-screen display for visualization and a standard display for management. In terms of visualization, the EVP allows the operator to visualize files, images, SMS, SDS, video, audio, and current or archival data on naval situation on digital maps. All the visualized data can be synchronized in time. In terms of generation of new visualization tasks, the EVP allows the operator to define a great number of parameters of the task. For both the generation of new tasks and the visualization of data, the EVP communicates with the CS, which, if necessary, communicates with the AS. In regard to visualization of naval situation on digital maps, the discussed fragment of the system can be considered a Vessel Traffic Service[...]

Stradar - rozproszony system dyspozytorski i teleinformatyczny dla Straży Granicznej DOI:10.15199/59.2017.11.1

  Warunkiem spełnienia zadań przez Straż Graniczną jest wyposażenie jej w odpowiedni system zbierania, przetwarzania, udostępniania danych dla ich analizy, wynikającej z potrzeb i działań operacyjnych [8, 9, 10, 13, 14, 15, 16, 17]. Rodzaj i zakres zbieranych danych oraz funkcjonalność systemu jest uzależniona od typu granicy, na której ma być zastosowany system. W artykule przedstawiono wynik projektu takiego systemu wykonanego dla obsługi morskiej granicy państwa. Projekt ten współfinansowało Narodowe Centrum Badań i Rozwoju. Celem było wykonanie demonstratora technologicznego, umożliwiającego eksplorację i archiwizację: sygnałów mowy, danych mapowych zawierających informacje AIS (Automatic Identification System), radarowe oraz GPS (Global Positioning System), sygnałów wideo, komunikatów SMS (Short Message service), kolekcjonowanych na serwerach archiwizacji włączonych w sieć IP Straży Granicznej. W skład demonstratora technologicznego wchodzą następujące elementy funkcjonalne, będące konsekwencją uwzględnienia wyników projektu KONSOLA [11] oraz wymagań i założeń przyjętych dla projektu STRADAR [11]: centrum, serwery archiwizacji SA, stanowisko wizualizacji zdarzeń SWZ, jednostka mobilna JM, punkt obserwacyjny PO. W celu realizacji projektu i przeprowadzenia badań, demonstrator technologiczny uzupełniono o dodatkowe środowisko badawcze, w skład którego wchodzą: system MCS IP, serwer webowy UM, sieć IP, komputery pomocnicze do symulacji i emulacji zdarzeń, tester protokołów. Podczas wykonywania projektu - na podstawie wyników przeprowadzonych badań i proponowanych koncepcji systemu STRADAR [1, 5] - zdefiniowano wymagania funkcjonalne demonstratora, dobrano technologie i narzędzia informatyczne, dokonano dekompozycji blokowo-funkcjonalnej urządzenia, określono zasoby sprzętowo-programowe dla jego realizacji. Na tej podstawie zrealizowano warstwę sprzętową demonstratora oraz wybrane elementy systemu MCS (Multifunctional Communi[...]

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