Synchronization of spatiotemporal semiconductor lasers and its application in color image encryption

Optical chaos is a topic of current research characterized by high-dimensional nonlinearity which is attributed to the delay-induced dynamics, high bandwidth and easy modular implementation of optical feedback. In light of these facts, which adds enough confusion and diffusion properties for secure communications, we explore the synchronization phenomena in spatiotemporal semiconductor laser systems. The novel system is used in a two-phase colored image encryption process. The high-dimensional chaotic attractor generated by the system produces a completely randomized chaotic time series, which is ideal in the secure encoding of messages. The scheme thus illustrated is a two-phase encryption method, which provides sufficiently high confusion and diffusion properties of chaotic cryptosystem employed with unique data sets of processed chaotic sequences. In this novel method of cryptography, the chaotic phase masks are represented as images using the chaotic sequences as the elements of the image. The scheme drastically permutes the positions of the picture elements. The next additional layer of security further alters the statistical information of the original image to a great extent along the three-color planes. The intermediate results during encryption demonstrate the infeasibility for an unauthorized user to decipher the cipher image. Exhaustive statistical tests conducted validate that the scheme is robust against noise and resistant to common attacks due to the double shield of encryption and the infinite dimensionality of the relevant system of partial differential equations.Comment: 20 pages, 11 figures; Article in press, Optics Communications (2011

Design and implementation of secure chaotic communication systems

Chaotic systems have properties such as ergodicity, sensitivity to initial conditions/parameter mismatches, mixing property, deterministic dynamics, structure complexity, to mention a few, that map nicely with cryptographic requirements such as confusion, diffusion, deterministic pseudorandomness, algorithm complexity. Furthermore, the possibility of chaotic synchronization, where the master system (transmitter) is driving the slave system (receiver) by its output signal, made it probable for the possible utilization of chaotic systems to implement security in the communication systems. Many methods like chaotic masking, chaotic modulation, inclusion, chaotic shift keying (CSK) had been proposed however, many attack methods later showed them to be insecure. Different modifications of these methods also exist in the literature to improve the security, but almost all suffer from the same drawback. Therefore, the implementation of chaotic systems in security still remains a challenge. In this work, different possibilities on how it might be possible to improve the security of the existing methods are explored. The main problem with the existing methods is that the message imprint could be found in the dynamics of the transmitted signal, therefore by some signal processing or pattern classification techniques, etc, allow the exposition of the hidden message. Therefore, the challenge is to remove any pattern or change in dynamics that the message might bring in the transmitted signal.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Security and Privacy for Modern Wireless Communication Systems

The aim of this reprint focuses on the latest protocol research, software/hardware development and implementation, and system architecture design in addressing emerging security and privacy issues for modern wireless communication networks. Relevant topics include, but are not limited to, the following: deep-learning-based security and privacy design; covert communications; information-theoretical foundations for advanced security and privacy techniques; lightweight cryptography for power constrained networks; physical layer key generation; prototypes and testbeds for security and privacy solutions; encryption and decryption algorithm for low-latency constrained networks; security protocols for modern wireless communication networks; network intrusion detection; physical layer design with security consideration; anonymity in data transmission; vulnerabilities in security and privacy in modern wireless communication networks; challenges of security and privacy in node–edge–cloud computation; security and privacy design for low-power wide-area IoT networks; security and privacy design for vehicle networks; security and privacy design for underwater communications networks

The collectors : Naval, Army and Air Intelligence in the New Zealand Armed Forces during the Second World War

This thesis examines the performance of the intelligence collection organisations of the armed services of New Zealand during the Second World War. It considers the intelligence bodies of the Navy, the Army and the Air Force and looks at their growth, development and demise, and assesses their effectiveness as intelligence organisations. The question of how much New Zealand could be expected to achieve in the field of intelligence arises, not least because New Zealand was demographically small, had a long coastline and was geographically relatively remote. How much could New Zealand contribute to the Allied cause in intelligence terms is another issue, and what forms did any participation take? Were there lessons to be learned from the wartime experience (there were, but they went for the most part largely unheeded)? New Zealand, like other countries, had a fragmented approach to intelligence collection, making for a degree of complexity over a range of activity, despite the intelligence organisations being of modest size. The examination of the organisations in this thesis includes multi-service and multi-departmental dimensions along with the production of useful intelligence. Whether good use was made of intelligence collected is another matter. There was a substantial amount of liaison, contact and practice between departments of state as to various aspects of intelligence, the Organization for National Security and coastwatching being two notable areas. The overarching role and limitations of the Organization for National Security with regard to intelligence is explored, and the development of a combined intelligence centre examined. The participation of New Zealand signals intelligence organisations in the great Allied interception offensive is detailed, along with the mundane but fundamental task of coastal surveillance. The establishment and spectacular decline of the first local independent security service is traced. Both the intelligence and security aspects of the Army's operationally deployed units are covered, along with the growth of RNZAF air intelligence. The effectiveness of all of these organisations could hardly be expected to be uniform, and indeed it was not. Some bodies succeeded in their collection roles beyond expectations, others were reasonably effective, and two organisations failed dismally in different ways, for a number of reasons. If a pattern emerges at all, it is that small single service component-type intelligence sections collecting operational intelligence were the most effective New Zealand intelligence organisations. Operational focus and. operational requirements underlay the drive for successful collection. Most significant within the Allied context were the signals intelligence bodies. At the other end of the scale, larger co-operative interdepartmental New Zealand intelligence ventures failed to deliver projected results. New Zealand's armed forces had an interesting variety of intelligence contributions during the Second World War. Of these, the most effective organisations collected intelligence to meet directed operational requirements

Mobile Ad-Hoc Networks

Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: vehicular ad-hoc networks, security and caching, TCP in ad-hoc networks and emerging applications. It is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

Mercury of the Waves: Modern Cryptology and U.S. Literature

Mercury of the Waves: Modern Cryptology and U.S. LiteratureHenry VeggianUniversity of Pittsburgh, 2005The doctoral dissertation examines United States literary and institutional history during the period 1900-1973. The study demonstrates how cryptology was detached from its philological residence over three phases (the amateur, institutional, and professional). In the amateur phase, which was regionally specific to the Midwest, the science was characterized by social reformist debate. In the second, institutional phase, the amateur version of cryptology was institutionalized by the United States federal government following WWI to imitate a specific institutional model (that of the French Bureau du Chiffre). During the third, professional phase, the prior two were enhanced during the interwar period by linguists, mechanical engineers, literary modernists, and cryptologists. Running parallel to this narrative is a modern American literary genealogy that, beginning with Henry Adams and extending through Thomas Pynchon, engaged cryptology during that same era. The dissertation locates their discourse within Vichian humanism, and in doing so it first explains how modern literature (and the American novel in particular), its practices, and institutions contributed discursive rhetoric, hermeneutical methods, and institutional models to the emergent 20th century U.S. security state; secondly, it argues that a particular genealogical style that spans the writings of Henry Adams, T.S. Eliot, William Faulkner, Raymond Chandler, and Thomas Pynchon elaborated an diverse rhetorical discourse by which to respond to that assemblage of new institutional entities, and without which that assemblage would be incoherent