Cryptanalysis of LFSR-based Pseudorandom Generators - a Survey

Pseudorandom generators based on linear feedback shift registers (LFSR) are a traditional building block for cryptographic stream ciphers. In this report, we review the general idea for such generators, as well as the most important techniques of cryptanalysis

Investigations in the design and analysis of key-stream generators

iv+113hlm.;24c

On Cryptographic Properties of LFSR-based Pseudorandom Generators

Pseudorandom Generators (PRGs) werden in der modernen Kryptographie verwendet, um einen kleinen Startwert in eine lange Folge scheinbar zufälliger Bits umzuwandeln. Viele Designs für PRGs basieren auf linear feedback shift registers (LFSRs), die so gewählt sind, dass sie optimale statistische und periodische Eigenschaften besitzen. Diese Arbeit diskutiert Konstruktionsprinzipien und kryptanalytische Angriffe gegen LFSR-basierte PRGs. Nachdem wir einen vollständigen Überblick über existierende kryptanalytische Ergebnisse gegeben haben, führen wir den dynamic linear consistency test (DLCT) ein und analysieren ihn. Der DLCT ist eine suchbaum-basierte Methode, die den inneren Zustand eines PRGs rekonstruiert. Wir beschließen die Arbeit mit der Diskussion der erforderlichen Zustandsgröße für PRGs, geben untere Schranken an und Beispiele aus der Praxis, die veranschaulichen, welche Größe sichere PRGs haben müssen

Multi-modal Active Authentication of Smartphone Users

With the increasing usage of smartphones not only as communication devices but also as the port of entry for a wide variety of user accounts at different information sensitivity levels, the need for hassle-free authentication is on the rise. Going beyond the traditional one-time authentication concept, active authentication (AA) schemes are emerging which authenticates users periodically in the background without the need for any user interaction. The purpose of this research is to explore different aspects of the AA problem and develop viable solutions by extracting unique biometric traits of the user from the wide variety of usage data obtained from Smartphone sensors. The key aspects of our research are the development of different components of user verification algorithms based on (a) face images from the front camera and (b) data from modalities other than the face. Since generic face detection algorithms do not perform very well in the mobile domain due to a significant presence of occluded and partially visible faces, we propose facial segment-based face detection technique to handle the challenge of partial faces in the mobile domain. We have developed three increasingly accurate proposal-based face detection methods, namely Facial Segment-based Face Detector (FSFD), SegFace and DeepSegFace, respectively, which perform binary classification on the results of a novel proposal generator that utilizes facial segments to obtain face-proposals. We also propose the Deep Regression-based User Image Detector (DRUID) network which shifts from the classification to the regression paradigm to avoid the need for proposal generation and thereby, achieves better processing speed and accuracy. DeepSegFace and DRUID have unique network architectures with customized loss functions and utilize a novel data augmentation scheme to train on a relatively small amount of data. The proposed methods, especially DRUID show superior performance over other state-of-the-art face detectors in terms of precision-recall and ROC curve on two mobile face datasets. We extended the concept of facial-segments to facial attribute detection for partially visible faces, a topic rarely addressed in the literature. We developed a deep convolutional neural network-based method named Segment-wise, Partial, Localized Inference in Training Facial Attribute Classification Ensembles (SPLITFACE) to detect attributes reliably from partially occluded faces. Taking several facial segments and the full face as input, SPLITFACE takes a data-driven approach to determine which attributes are localized in which facial segments. The unique architecture of the network allows each attribute to be predicted by multiple segments, which permits the implementation of committee machine techniques for combining local and global decisions to boost performance. Our evaluations on the full CelebA and LFWA datasets and their modified partial-visibility versions show that SPLITFACE significantly outperforms other recent attribute detection methods, especially for partial faces and for cross-domain experiments. We also explored the potentials of two less popular modalities namely, location history and application-usage, for active authentication. Aiming to discover the pattern of life of a user, we processed the location traces into separate state space models for each user and developed the Marginally Smoothed Hidden Markov Model (MSHMM) algorithm to authenticate the current user based on the most recent sequence of observations. The method takes into consideration the sparsity of the available data, the transition phases between states, the timing information and also the unforeseen states. We looked deeper into the impact of unforeseen and unknown states in another research work where we evaluated the feasibility of application usage behavior of the users as a potential solution to the active authentication problem. Our experiments show that it is essential to take unforeseen states into account when designing an authentication system with sparse data and marginal-smoothing techniques are very useful in this regard. We conclude this dissertation with the description of some ongoing efforts and future directions of research related the topics discussed in addition to a summary of all the contributions and impacts of this research work

Satellite Communications

This study is motivated by the need to give the reader a broad view of the developments, key concepts, and technologies related to information society evolution, with a focus on the wireless communications and geoinformation technologies and their role in the environment. Giving perspective, it aims at assisting people active in the industry, the public sector, and Earth science fields as well, by providing a base for their continued work and thinking

Abstracts on Radio Direction Finding (1899 - 1995)

The files on this record represent the various databases that originally composed the CD-ROM issue of "Abstracts on Radio Direction Finding" database, which is now part of the Dudley Knox Library's Abstracts and Selected Full Text Documents on Radio Direction Finding (1899 - 1995) Collection. (See Calhoun record https://calhoun.nps.edu/handle/10945/57364 for further information on this collection and the bibliography). Due to issues of technological obsolescence preventing current and future audiences from accessing the bibliography, DKL exported and converted into the three files on this record the various databases contained in the CD-ROM. The contents of these files are: 1) RDFA_CompleteBibliography_xls.zip [RDFA_CompleteBibliography.xls: Metadata for the complete bibliography, in Excel 97-2003 Workbook format; RDFA_Glossary.xls: Glossary of terms, in Excel 97-2003 Workbookformat; RDFA_Biographies.xls: Biographies of leading figures, in Excel 97-2003 Workbook format]; 2) RDFA_CompleteBibliography_csv.zip [RDFA_CompleteBibliography.TXT: Metadata for the complete bibliography, in CSV format; RDFA_Glossary.TXT: Glossary of terms, in CSV format; RDFA_Biographies.TXT: Biographies of leading figures, in CSV format]; 3) RDFA_CompleteBibliography.pdf: A human readable display of the bibliographic data, as a means of double-checking any possible deviations due to conversion

Compilation and critique : the essay as a literary, cinematographic and videographic form

This dissertation critically engages the meaning and scope of the category of the ‘essay film’; a term that has gained increasing currency in recent decades in film studies and contemporary art to group a diverse array of moving-image works. Departing from recent literature on the essay film, the essay, as I argue, should be conceived less as a stable generic category, than as a dynamic form and experimental mode of writing and filmmaking, which employs and cuts across diverse literary, cinematic and televisual genres and sub-genres, and which is historically subject to critical transformation as it encounters new social, technological and cultural forms and mediums. The introduction provides a critical survey of some of the leading proponents of the essay film, and outlines a working definition of the essay as a literary and cinematographic form. Chapter 1 examines the history of the essay and criticism as a literary and philosophical form, focusing on the essayistic and critical writings of Michel de Montaigne, the early German Romantics, Walter Benjamin, Theodor W. Adorno and Roland Barthes. Central to the critical and experimental nature of the essay, as the chapter underlines, is the deployment of various indirect, allegorical, and modernist rhetorical and poetic strategies and devices – such as citation, irony, fragmentation, and parataxis – which attempt to engage the reader in the text’s reflective process through the constellation of enigmatic and disjunct moments and perspectives. Chapter 2 explores the emergence of various essayistic forms in the Soviet avant-garde in the 1920s, relating debates around the privileging of literary and photographic documentary montage practices in Soviet Factography to Esfir Shub’s historical compilation films, Dziga Vertov’s experimental newsreels, and Sergei Eisenstein’s project to make a plotless film-essay based on Karl Marx’s Capital. Chapter 3 focuses on Jean-Luc Godard’s film and video essays – from Camera Eye (1967) to Histoire(s) du cinéma (1988-1998) – delineating the crucial shifts in Godard’s various attempts to present a critical discourse on cinema and the media through the montage of image and sound. Chapter 4 investigates the essay films, archival video essays, and essayistic video installations of Harun Farocki, attending to how his works endeavour to render the ciphered social life of images and the historical transformations in technologies and techniques of seeing and imaging available for critical interpretation. Central to my account of the essay as a literary, cinematographic, and videographic form is the question of compilation; namely, how (from Montaigne to Farocki) knowledge and history (whether in the form of text or image) is archived and assembled through the juxtaposition and critical weighing of disparate citations and images. Paramount in relation to Godard and Farocki, as I underscore, is their respective shifts to working with video technology, which afforded both filmmakers the capacity to more freely combine and analyze images from divergent media sources, as well as to devise novel forms of videographic montage based on the construction of historical correspondences between audio-visual elements. I conclude the dissertation with a consideration of the impact of digital technology on contemporary essayistic audio-visual practices, and how issues raised in the preceding chapters – around audio-visual criticism, the spatialization of montage in moving-image installation work, and documentary and archival film practices – have been affected by such technological and cultural shifts

General Catalog 2002-2004

Contains course descriptions, University college calendar, and college administrationhttps://digitalcommons.usu.edu/universitycatalogs/1123/thumbnail.jp