Visual cryptography with cheating shares

Visual cryptography is a technique that applies the human visual system to decode encrypted information, such as text, image and number, without any sophisticated devices and computing capabilities. Therefore, compared with the traditional cryptography, it is apparent that it saves a large amount of time and money on devices and computations. Also, visual cryptography provides the convenience for humans to carry out decryption with a portal card which is significant to the business application. In the past decade, visual cryptography has been thoroughly researched not only on its contrast and subpixel expansion, but also on its applications. The main contribution of this thesis is the security of visual cryptography related to the dishonest shareholders. This is the first known work concerning this variety of potentially secure problem. In the previous papers, the shareholders are inherently honest. However, in the real world, it is impossible to guarantee that every shareholder would be honest forever(e.g., because of the interest of business or military, some shareholders might change to be the traitors). Therefore, a new method based on visual authentication[16] is proposed and the improvement is also made. In this thesis, we also review the previous papers on different fields of the visual cryptography

Connected Attribute Filtering Based on Contour Smoothness

A new attribute measuring the contour smoothness of 2-D objects is presented in the context of morphological attribute filtering. The attribute is based on the ratio of the circularity and non-compactness, and has a maximum of 1 for a perfect circle. It decreases as the object boundary becomes irregular. Computation on hierarchical image representation structures relies on five auxiliary data members and is rapid. Contour smoothness is a suitable descriptor for detecting and discriminating man-made structures from other image features. An example is demonstrated on a very-high-resolution satellite image using connected pattern spectra and the switchboard platform

Argument as design: a multimodal approach to academic argument in a digital age

Includes bibliographical referencesThis study posits that using a range of modes and genres to construct argument can engender different ways of thinking about argument in the academic context. It investigates the potentials and constraints of adopting a multimodal approach to constructing academic argument. The research is situated within a seminar, in a second year Media course. Within this context, the study identifies the semiotic resources that students draw on and examines how they are employed to construct academic argument in three digital domains, namely video, comics and PowerPoint. Grounded in a theory of multimodal social semiotics, this study posits that argument is a product of design, motivated by the rhetor's interest in communicating a particular message, in a particular environment, and shaped by the available resources in the given environment. It proposes that argument is a cultural text form for bringing about difference (Kress 1989). This view of argument recognises that argument occurs in relation to mode, genre, discourse and medium. The study illustrates how each of these social categories shapes argument through textual analysis. A framework based on Halliday's metafunctional principle is proposed to analyse argument in multimodal texts. The framework combines theories from rhetoric and social semiotics. It offers analysis of ideational content, the ways social relations are established, and how organising principles assist in establishing coherence in argument. The analysis of the data (video, comics and PowerPoint presentations) demonstrates that the framework can be applied across genres and media. The significance of the study is threefold. Theoretically, it contributes towards theorising a theory of argument from a multimodal perspective. Methodologically, it puts forward a framework for analysing multimodal arguments. Pedagogically, it contributes towards developing and interrogating a pedagogy of academic argument that is relevant to contemporary communication practices

Teoria multikulttuurisista teksteistä : Erik Bergmanin musiikki multikulttuurisen Euroopan ilmiönä

This dissertation is a study of musical cultural mixtures, essentially focusing on mixtures in contemporary European art music and compositions of the Finnish-Swedish composer Erik Bergman as a complex case of cultural mixtures and mixing processes. The study suggests a theoretical framework and analytical tools for interpreting and deconstructing mixtures defined as multicultural texts. In the second part of the project, the suggested tools are applied to analyse the music of Erik Bergman, whose work is considered to be a particular example of the multicultural texts, in which the initial cultural components have blended into fusion on the level of sound. The project creates various perspectives to study the subject of musical mixtures described as virtual models of cultural communication, where different cultural identities, discourses, and aesthetics are presented simultaneously. Having as its goal the identifying and highlighting of different aspects of mixtures and strategies of their modelling, the multidisciplinary project, with a primary background in musicology and semiotics, combines diverse theories and concepts, involving different branches of semiotics (from Yuri Lotman s cultural semiotics to the intertextual studies and interpretative semiotics of Umberto Eco), as well as the concept of virtual reality, temporal theories, studies of cultural identity, the theory of topics, and studies of cultural forms of sound and their conceptualisation. The research work results in the creation of a comprehensive theory that proposes background, terminology, and several tools and strategies for studying mixtures, while tracing cultural information and its transformation inside them. The theory takes into account processes of virtual cultural modelling, the role of the author and the reader, and addresses an extensive category of the multicultural texts taken as personal creations. This novel understanding of musical mixtures leads to an analysis of mixtures on the level of sound essence and sound strategies. The research also creates a new perspective on Erik Bergman s music, an author with extraordinary cultural experiences and many cultural identities speaking through his authorial voice. The analytical part of the project demonstrates how diverse strategies of modelling, cultural compositional techniques, and sound strategies work to compose (and decompose) a multicultural text.Väitöskirja on tutkielma musiikillis-kulttuurisista sekoittumista pääkohteenaan sekoittumat ( mixtures ) modernissa eurooppalaisessa taidemusiikissa ja suomenruotsalaisen säveltäjän Erik Bergmanin sävellyksissä kulttuuristen sekoittumien ja sekoittumisprosessien kompleksisena esimerkkitapauksena. Tutkielma esittelee teoreettisen viitekehyksen ja menetelmät näiden sekoittumien musiikilliselle analyysille ja tulkinnalle. Väitöskirjan toisessa osassa edellä mainittuja menetelmiä sovelletaan Erik Bergmanin musiikin analyysiin. Hänen tuotantoaan tarkastellaan musiikillisten sekoittumien erityislaatuisena esimerkkinä, jossa alkujaan kulttuuriset komponentit sulautuvat yhteen äänen tasolla. Tutkielman kontekstissa musiikilliset sekoittumat määritellään multikulttuurisiksi teksteiksi. Näitä voidaan kuvailla kulttuurisen kommunikaation virtuaalisina malleina, joissa erilaiset kulttuuriset identiteetit, diskurssit ja estetiikat esiintyvät samanaikaisesti. Tavoitteenaan identifioida ja tuoda esiin näiden sekoittumien erilaisia aspekteja ja niiden mallintamisen strategioita tämä monitieteellinen projekti, pääasiallisena taustanaan musiikkitiede ja semiotiikka, luo erilaisia perspektiivejä musiikillisten sekoittumien tutkimiseen. Siten se yhdistää useita teorioita ja käsitteitä semiotiikan erilaiset alat mukaan lukien (Juri Lotmanin kulttuurisemiotiikasta Umberto Econ intertekstuaalisiin tutkielmiin ja tulkitsevaan semiotiikkaan). Tutkielma kytkee myös toisiinsa virtuaalisen todellisuuden käsitteen, ajallisuutta koskevat teoriat, tutkimukset kulttuurisesta identiteetistä, toposteorian ja äänen kulttuuriset ilmenemismuodot ja niiden käsitteellistämisen. Väitöskirjan tulos on monipuolinen teoria, joka esittelee taustan ja terminologian sekä erilaiset menetelmät ja strategiat sekoittumien ja niiden sisältämän kulttuurisen informaation ja transformaation tutkimiselle. Teoria käsittää myös virtuaalisen kulttuurisen mallintamisen prosessit, tekijän ja lukijan roolin sekä laaja-alaisen kategorian multikulttuurisista teksteistä yksilöllisinä luomuksina. Tämä uusi näkökulma musiikillisiin sekoittumiin johtaa niiden analyysiin äänen olemuksen ja strategioiden tasolla. Tutkimus avaa myös uusia näköaloja Erik Bergmanin musiikkiin ja niihin erityislaatuisiin kulttuurisiin kokemuksiin ja moniin kulttuurisiin identiteetteihin, jotka puhuvat hänen tekijän äänellään. Tutkimusprojektin analyyttinen osa osoittaa, kuinka mallintamisen erilaiset strategiat, säveltämisen kulttuuriset tekniikat ja äänistrategiat osallistuvat multikulttuuristen tekstien rakentumiseen (ja hajottamiseen)

Perceiving voids: Memory And Sight Afflictions In Contemporary Cinema

My thesis focuses on the perceptive afflictions caused by alteration of the normal biological functioning of sight and memory. These afflictions are related to the redefinition and disgregation of the classical and postclassical cinematographic characters, and affect cinematographic language, establishing a dialectical relation with the filmic image that contaminates our spectatorial perception. In the first chapter I propose a different reading of a few moments in film history, turning points in which a modification of the ordinary sensorial patterns has been introduced. From the German Expressionism to the late authorial experiments of the 60s, there is a sort of hidden history of film that passes through the continuous redefinition of the audience sensory activity. The different perspective upon broadly studied topics leads to the analysis of contemporary cinema: my thesis tries to investigate the reasons that led cinema to continually increase the representation of perceptive afflictions during the last years, and theses “affected” narratives of afflictions and dysfunctions have interesting effects upon so called “normal” perception of the reality surrounding us. The chapters 2 and 3 respectively analyze memory disorders and different dysfunctions of sight: these elements determine alterations in the ‘normal’ and ‘sensory’ perception of reality. They work as narrative factors changing the visual filmic instruments and redefining the role of the subject (and his/her uncertain definition of identity) in contemporary narratives that show how new technologies are profoundly transforming (and enhancing) the perceptive mechanisms involved in our spectatorial activity. In this work I analyze those films that are mostly committed to a clear and readable narration. My study primarily concentrates on American cinema of the last 30 years – with particular attention to popular Hollywood productions – because Hollywood has become the privileged ‘laboratory’ for the negotiation of gaze and images in the contemporary mediascape (while during the classical era experimental and avant-garde cinema were the “place” in which audience experienced the most important redefinitions of the boundaries between different types of mediated perception

Hardware-Based Authentication for the Internet of Things

Entity authentication is one of the most fundamental problems in computer security. Implementation of any authentication protocol requires the solution of several sub-problems, such as the problems regarding secret sharing, key generation, key storage and key verification. With the advent of the Internet-of-Things(IoT), authentication becomes a pivotal concern in the security of IoT systems. Interconnected components of IoT devices normally contains sensors, actuators, relays, and processing and control equipment that are designed with the limited budget on power, cost and area. As a result, incorporating security protocols in such resource constrained IoT components can be rather challenging. To address this issue, in this dissertation, we design and develop hardware oriented lightweight protocols for the authentication of users, devices and data. These protocols utilize physical properties of memory components, computing units, and hardware clocks on the IoT device. Recent works on device authentication using physically uncloneable functions can render the problem of entity authentication and verification based on the hardware properties tractable. Our studies reveal that non-linear characteristics of resistive memories can be useful in solving several problems regarding authentication. Therefore, in this dissertation, first we explore the ideas of secret sharing using threshold circuits and non-volatile memory components. Inspired by the concepts of visual cryptography, we identify the promises of resistive memory based circuits in lightweight secret sharing and multi-user authentication. Furthermore, the additive and monotonic properties of non-volatile memory components can be useful in addressing the challenges of key storage. Overall, in the first part of this dissertation, we present our research on design of low-cost, non-crypto based user authentication schemes using physical properties of a resistive memory based system. In the second part of the dissertation, we demonstrate that in computational units, the emerging voltage over-scaling (VOS)-based computing leaves a process variation dependent error signature in the approximate results. Current research works in VOS focus on reducing these errors to provide acceptable results from the computation point of view. Interestingly, with extreme VOS, these errors can also reveal significant information about the underlying physical system and random variations therein. As a result, these errors can be methodically profiled to extract information about the process variation in a computational unit. Therefore, in this dissertation, we also employ error profiling techniques along with the basic key-based authentication schemes to create lightweight device authentication protocols. Finally, intrinsic properties of hardware clocks can provide novel ways of device fingerprinting and authentication. The clock signatures can be used for real-time authentication of electromagnetic signals where some temporal properties of the signal are known. In the last part of this dissertation, we elaborate our studies on data authentication using hardware clocks. As an example, we propose a GPS signature authentication and spoofing detection technique using physical properties such as the frequency skew and drift of hardware clocks in GPS receivers