47 research outputs found

    Improved Attack on the Cellular Authentication and Voice Encryption Algorithm

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    We present new cryptanalysis of the Telecommunications hash algorithm known as Cellular Authentication and Voice Encryption Algorithm (CAVE). The previous guess-and-determine style reconstruction attack requires 2912^{91} (resp. 2932^{93}) evaluations of CAVE-4 (resp. CAVE-8) to find a single valid pre-image (one which satisfies the input redundancy). Here we present a new attack that finds emph{all} valid pre-images with effort equivalent to around 2722^{72} evaluations of the algorithm for both CAVE-4 and CAVE-8

    Some Words on Cryptanalysis of Stream Ciphers

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    In the world of cryptography, stream ciphers are known as primitives used to ensure privacy over a communication channel. One common way to build a stream cipher is to use a keystream generator to produce a pseudo-random sequence of symbols. In such algorithms, the ciphertext is the sum of the keystream and the plaintext, resembling the one-time pad principal. Although the idea behind stream ciphers is simple, serious investigation of these primitives has started only in the late 20th century. Therefore, cryptanalysis and design of stream ciphers are important. In recent years, many designs of stream ciphers have been proposed in an effort to find a proper candidate to be chosen as a world standard for data encryption. That potential candidate should be proven good by time and by the results of cryptanalysis. Different methods of analysis, in fact, explain how a stream cipher should be constructed. Thus, techniques for cryptanalysis are also important. This thesis starts with an overview of cryptography in general, and introduces the reader to modern cryptography. Later, we focus on basic principles of design and analysis of stream ciphers. Since statistical methods are the most important cryptanalysis techniques, they will be described in detail. The practice of statistical methods reveals several bottlenecks when implementing various analysis algorithms. For example, a common property of a cipher to produce n-bit words instead of just bits makes it more natural to perform a multidimensional analysis of such a design. However, in practice, one often has to truncate the words simply because the tools needed for analysis are missing. We propose a set of algorithms and data structures for multidimensional cryptanalysis when distributions over a large probability space have to be constructed. This thesis also includes results of cryptanalysis for various cryptographic primitives, such as A5/1, Grain, SNOW 2.0, Scream, Dragon, VMPC, RC4, and RC4A. Most of these results were achieved with the help of intensive use of the proposed tools for cryptanalysis

    Wireless Network Security and Interworking

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    The Cryptographic Imagination

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    Originally published in 1996. In The Cryptographic Imagination, Shawn Rosenheim uses the writings of Edgar Allan Poe to pose a set of questions pertaining to literary genre, cultural modernity, and technology. Rosenheim argues that Poe's cryptographic writing—his essays on cryptography and the short stories that grew out of them—requires that we rethink the relation of poststructural criticism to Poe's texts and, more generally, reconsider the relation of literature to communication. Cryptography serves not only as a template for the language, character, and themes of much of Poe's late fiction (including his creation, the detective story) but also as a "secret history" of literary modernity itself. "Both postwar fiction and literary criticism," the author writes, "are deeply indebted to the rise of cryptography in World War II." Still more surprising, in Rosenheim's view, Poe is not merely a source for such literary instances of cryptography as the codes in Conan Doyle's "The Dancing-Men" or in Jules Verne, but, through his effect on real cryptographers, Poe's writing influenced the outcome of World War II and the development of the Cold War. However unlikely such ideas sound, The Cryptographic Imagination offers compelling evidence that Poe's cryptographic writing clarifies one important avenue by which the twentieth century called itself into being. "The strength of Rosenheim's work extends to a revisionistic understanding of the entirety of literary history (as a repression of cryptography) and then, in a breathtaking shift of register, interlinks Poe's exercises in cryptography with the hyperreality of the CIA, the Cold War, and the Internet. What enables this extensive range of applications is the stipulated tension Rosenheim discerns in the relationship between the forms of the literary imagination and the condition of its mode of production. Cryptography, in this account, names the technology of literary production—the diacritical relationship between decoding and encoding—that the literary imagination dissimulates as hieroglyphics—the hermeneutic relationship between a sign and its content."—Donald E. Pease, Dartmouth Colleg

    Foresight and flexibility in cryptography and voice over IP policy

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Political Science, 2008."February 2008."Includes bibliographical references (p. 235-248).This main question in this dissertation is under what conditions government agencies show foresight in formulating strategies for managing emerging technologies. A secondary question is when they are capable of adaptation. Conventional wisdom and most organization theory literature suggest that organizations are reactive rather than proactive, reluctant to change, and responsive only to threats to their core mission or autonomy. The technological, economic, social, political, and sometimes security uncertainties that often accompany emerging technologies further complicate decision-making. More generally, organizations must often make decisions under conditions of limited information while guarding against lock-in effects that can constrain future choices. The two cases examined in this dissertation suggest that contrary to conventional wisdom, organizations can show foresight and flexibility in the management of emerging technologies. Key factors that promote foresight are: an organizational focus on technology, with the emerging technology in question being highly relevant to the organization's mission; technical expertise and a recognition of the limits of that knowledge; and experience dealing with other emerging technologies. The NSA recognized the inevitability of mass market encryption early on and adopted a sophisticated strategy of weakening the strength of, reducing the use of, and slowing down the deployment of mass market encryption in order to preserve its ability to easily monitor communications. The Agency showed considerable tactical adaptation in pursuit of this goal. The FCC adopted a rather unusual policy of forbearance toward VoIP. The Commission deliberately refrained from regulating VoIP in order to allow the technology to mature, innovation to occur, uncertainties to resolve, and to avoid potential market distortions due to too early or suboptimally formulated regulation. Eventually, however, pressure from outside interests such as law enforcement forced the Commission to act.by Shirley K. Hung.Ph.D

    Bridgewater College Catalog, Session 2015-16

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    https://digitalcommons.bridgewater.edu/college_catalogs/1119/thumbnail.jp

    Electronic Evidence and Electronic Signatures

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    In this updated edition of the well-established practitioner text, Stephen Mason and Daniel Seng have brought together a team of experts in the field to provide an exhaustive treatment of electronic evidence and electronic signatures. This fifth edition continues to follow the tradition in English evidence text books by basing the text on the law of England and Wales, with appropriate citations of relevant case law and legislation from other jurisdictions. Stephen Mason (of the Middle Temple, Barrister) is a leading authority on electronic evidence and electronic signatures, having advised global corporations and governments on these topics. He is also the editor of International Electronic Evidence (British Institute of International and Comparative Law 2008), and he founded the innovative international open access journal Digital Evidence and Electronic Signatures Law Review in 2004. Daniel Seng (Associate Professor, National University of Singapore) is the Director of the Centre for Technology, Robotics, AI and the Law (TRAIL). He teaches and researches information technology law and evidence law. Daniel was previously a partner and head of the technology practice at Messrs Rajah & Tann. He is also an active consultant to the World Intellectual Property Organization, where he has researched, delivered papers and published monographs on copyright exceptions for academic institutions, music copyright in the Asia Pacific and the liability of Internet intermediaries
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