1,942 research outputs found

    Introduction to Shipboard Weapons

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    On the Application of PSpice for Localised Cloud Security

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    The work reported in this thesis commenced with a review of methods for creating random binary sequences for encoding data locally by the client before storing in the Cloud. The first method reviewed investigated evolutionary computing software which generated noise-producing functions from natural noise, a highly-speculative novel idea since noise is stochastic. Nevertheless, a function was created which generated noise to seed chaos oscillators which produced random binary sequences and this research led to a circuit-based one-time pad key chaos encoder for encrypting data. Circuit-based delay chaos oscillators, initialised with sampled electronic noise, were simulated in a linear circuit simulator called PSpice. Many simulation problems were encountered because of the nonlinear nature of chaos but were solved by creating new simulation parts, tools and simulation paradigms. Simulation data from a range of chaos sources was exported and analysed using Lyapunov analysis and identified two sources which produced one-time pad sequences with maximum entropy. This led to an encoding system which generated unlimited, infinitely-long period, unique random one-time pad encryption keys for plaintext data length matching. The keys were studied for maximum entropy and passed a suite of stringent internationally-accepted statistical tests for randomness. A prototype containing two delay chaos sources initialised by electronic noise was produced on a double-sided printed circuit board and produced more than 200 Mbits of OTPs. According to Vladimir Kotelnikov in 1941 and Claude Shannon in 1945, one-time pad sequences are theoretically-perfect and unbreakable, provided specific rules are adhered to. Two other techniques for generating random binary sequences were researched; a new circuit element, memristance was incorporated in a Chua chaos oscillator, and a fractional-order Lorenz chaos system with order less than three. Quantum computing will present many problems to cryptographic system security when existing systems are upgraded in the near future. The only existing encoding system that will resist cryptanalysis by this system is the unconditionally-secure one-time pad encryption

    The Impact of the Crisis on Employment and the Role of Labour Market Institutions

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    The paper takes a comparative perspective on the labour market impact on G20 and EU countries of the financial and economic crisis that began in 2008. It starts from the observation that the decline in employment and rise in unemployment in relation to output or GDP reductions varies significantly across countries. It examines the impacts from an institutional perspective taking into account different channels of external, internal and wage flexibility determined by both the institutional arrangements in place before the crisis and discretionary reforms implemented during the crisis. Emphasis is placed on the role of permanent and temporary jobs, working time adjustment, wage flexibility and active and passive labour market policies. The paper shows that, at least for the time being, unemployment increases have been contained in countries with comparatively strong internal flexibility. At the same time, however, it appears that the crisis has – at least in some cases – contributed to a further dualization of labour markets given that risks are allocated unequally across types of employment.crisis, employment, EPL, institutions, dual labour markets, flexibility

    Chaos-based Cryptography for Cloud Computing

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    Cloud computing and poor security issues have quadrupled over the last six years and with the alleged presence of backdoors in common encryption ciphers, has created a need for personalising the encryption process by the client. In 2007, two Microsoft employees gave a presentation ``On the Possibility of a backdoor in the NIST SP800-90 Dual Elliptic Curve Pseudo Random Number Generators\u27\u27 and was linked in 2013 by the New York Times with notes leaked by Edward Snowden. This confirmed backdoors were placed, allegedly, in a number of encryption systems by the National Security Agency, which if true creates an urgent need for personalising the encryption process by generating locally unbreakable one-time pad ciphers. Hybrid random binary sequences from chaotic oscillators initialised by natural noise, were exported to an online Javascript application which applies a von Neumann deskewing algorithm to improve the cryptographic strength of the encryptor. The application also provides initial statistical p-test for randomness testing. Encoding the \textit{Lenna} image by XORing it with the new cipher provided another test to observe if patterns could be observed in the encoded image. Finally, the cipher was subjected to the NIST suite of statistical tests. All designs were simulated using Orcad PSpice Š^{\copyright} V16.

    On the Development of a One-Time Pad Generator for Personalising Cloud Security

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    Cloud computing security issues are being reported in newspapers, television, and on the Internet, on a daily basis. Furthermore, in 2013, Edward Snowden alleged backdoors were placed in a number of encryption systems by the National Security Agency causing confidence in public encryption to drop even further. Our solution allows the end-user to add a layer of unbreakable security by encrypting the data locally with a random number generator prior to uploading data to the Cloud. The prototype one-time pad generator is impervious to cryptanalysis because it generates unbreakable random binary sequences from chaos sources initiated from a natural noise. Specialised one-to-Cloud applications for this device means key distribution problems do not exist, even when used at different locations. A JavaScript application maximised the encryptor key entropy using a von Neumann algorithm and modulo-two arithmetic, where the key passed the National Institute of Standards and Technology statistical suite of tests. It is hoped that the final size of the generator should be similar to a typical Universal Serial Bus device

    The Chirp Function Revisited: A Uniqueness Conjecture for Chirplet Modulation

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    The chirp function (a unit amplitude quadratic phase-only function with linear frequency modulation) is well known and is used in a wide range of applications including radar, digital communications, information coding and hiding and many other forms of signal and image processing. This is because the chirp provides an optimal solution to the problem of retrieving information from low energy signals with a low Signal-to-Noise Ratio (SNR). The chirp function also occurs in the solution to many mathematical models used to describe the propagation and scattering of waves (in the Fresnel zone), in quantum mechanics (the quantum shutter problem) and optical fiber communications to name but a few. In a ‘systems and signals’ context, the chirp function is accepted to be unique in that no other function has properties which yield such an optimal solution to the problem of extracting information from noise. In this context, we revisit the chirp function, consider a theorem and conjecture that attempt to quantify its unique properties through an analysis of its Fourier transform and re-establish the principles associated with the chirplet transform for functions of compact support. We then consider the principles of chirplet modulation for the transmission and reconstruction of bit-streams from signals with a low SNRs and show how this approach can be used to secure chirplet modulated signals using the prime number factorisation of a semi-prime derived from the value of the bandwidth of a communications channel

    Entropy, Information, Landauer’s limit and Moore’s law

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    In this paper we explore the link between information and entropy by considering the infamous Maxwell demon thought experiment. A non-rigorous mathematical solution by Le´o Szil´ard established this link for the first time, as did Claude Shannon nineteen years later. In 1961, Rolf Landauer’s mathematical solution resulted in the Landauer limit, which is still being hotly debated, but here we discuss the implication of this limit on Moore’s law and future growth in computing power. A workaround the limit is proposed using an Analogue Artificial Neural Network (AANN). Here, we mimic the action of a human brain synapse formed from memristance connected between two Fitzhugh-Nagumo (FN) neuron models. All designs were simulated in OrCAD PSpice version 16.5, but a master-slave synapse was built, tested and outputs compared to simulation results. The synapse was also connected in a star-type network which displayed chaotic-type behaviour for certain parameter values

    Secrecy and Randomness: Encoding Cloud data Locally using a One-Time Pad

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    There is no secrecy without randomness, and we address poor cloud security using an analogue chaotic onetime pad encryption system to achieve perfect secrecy. Local encoding returns control to the client and makes stored cloud data unreadable to an adversary. Most cloud service providers encode client data using public encryption algorithms, but ultimately businesses and organisations are responsible for encoding data locally before uploading to the Cloud. As recommended by the Cloud Security Alliance, companies employing authentication and local encryption will reduce or eliminate, EU fines for late data breach discoveries when the EU implements the new general data protection regulations in 2018. Companies failing to detect data breaches within a 72-hour limit will be fined up to four percent of their global annual turnover and estimates of several hundred billion euros could be levied in fines based on the present 146 days average EU breach discovery. The proposed localised encryption system is additional to public encryption, and obeying the rules of one-time pad encryption will mean intercepted encrypted data will be meaningless to an adversary. Furthermore, the encoder has no key distribution problem because applications for it are of “one-to-cloud” type
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