44 research outputs found

    A chaotic image encryption scheme owning temp-value feedback

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    This paper presents a novel efficient chaotic image encryption scheme, in which the temp-value feedback mechanism is introduced to the permutation and diffusion procedures. Firstly, a simple trick is played to map the plain-image pixels to the initial condition of the Logistic map. Then, a pseudorandom number sequence (PRNS) is obtained from iterating the map. The permutation procedure is carried out by a permutation sequence which is generated by comparing the PRNS and its sorted version. The diffusion procedure is composed of two reversely executed rounds. During each round, the current plain-image pixel and the last cipher-image pixel are used to produce the current cipher-image pixel with the help of the Logistic map and a pseudorandom number generated by the Chen system. To enhance the efficiency, only expanded XOR operation and modulo 256 addition are employed during diffusion. Experimental results show that the new scheme owns a large key space and can resist the differential attack. It is also efficient.Comment: 10 pages, 4 figure

    Chosen-plaintext attack of an image encryption scheme based on modified permutation-diffusion structure

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    Since the first appearance in Fridrich's design, the usage of permutation-diffusion structure for designing digital image cryptosystem has been receiving increasing research attention in the field of chaos-based cryptography. Recently, a novel chaotic Image Cipher using one round Modified Permutation-Diffusion pattern (ICMPD) was proposed. Unlike traditional permutation-diffusion structure, the permutation is operated on bit level instead of pixel level and the diffusion is operated on masked pixels, which are obtained by carrying out the classical affine cipher, instead of plain pixels in ICMPD. Following a \textit{divide-and-conquer strategy}, this paper reports that ICMPD can be compromised by a chosen-plaintext attack efficiently and the involved data complexity is linear to the size of the plain-image. Moreover, the relationship between the cryptographic kernel at the diffusion stage of ICMPD and modulo addition then XORing is explored thoroughly

    The Design and Its Application in Secure Communication and Image Encryption of a New Lorenz-Like System with Varying Parameter

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    A new Lorenz-like chaotic system with varying parameter is proposed by adding a state feedback function. The structure of the new designed system is simple and has more complex dynamic behaviors. The chaos behavior of the new system is studied by theoretical analysis and numerical simulation. And the bifurcation diagram shows a chaos-cycle-chaos evolution when the new parameter changes. Then a new synchronization scheme by a single state variable drive is given based on the new system and a chaotic parameter modulation digital secure communication system is also constructed. The results of simulation demonstrate that the new proposed system could be well applied in secure communication. Otherwise, based on the new system, the encryption and decryption of image could be achieved also

    A review of compressive sensing in information security field

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    The applications of compressive sensing (CS) in the fi eld of information security have captured a great deal of researchers\u27 attention in the past decade. To supply guidance for researchers from a comprehensive perspective, this paper, for the fi rst time, reviews CS in information security field from two aspects: theoretical security and application security. Moreover, the CS applied in image cipher is one of the most widespread applications, as its characteristics of dimensional reduction and random projection can be utilized and integrated into image cryptosystems, which can achieve simultaneous compression and encryption of an image or multiple images. With respect to this application, the basic framework designs and the corresponding analyses are investigated. Speci fically, the investigation proceeds from three aspects, namely, image ciphers based on chaos and CS, image ciphers based on optics and CS, and image ciphers based on chaos, optics, and CS. A total of six frameworks are put forward. Meanwhile, their analyses in terms of security, advantages, disadvantages, and so on are presented. At last, we attempt to indicate some other possible application research topics in future

    Development of semiconductor light sources for photonic-enabled quantum communication

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    Quantum information technologies have attracted tremendous attentions and development efforts by worldwide research organizations and governments in the past decades. It comprises the generation, manipulation, and transfer of quantum bits `qubits' based on the laws of quantum mechanics, enabling the applications of quantum metrology, quantum computation, quantum communication, etc. As one of the frontier quantum technologies, quantum communication features unconditionally secure data transfer between parties over long distance in theory, which can be accomplished through quantum state of light photons, due to their weak interaction with the environment and their remaining coherence over long distance. Meanwhile, quantum repeaters, similar as amplifier in classical communication are believed to be indispensable components to address the photon absorption and decoherence in noisy quantum channels, which scales exponentially with the distance. Quantum repeaters generally consist of three basic elements, namely entanglement swapping, entanglement purification, and quantum memories. In spite of significant breakthroughs achieved with a variety of optical protocols theoretically and experimentally, lack of near-perfect deterministic light sources with fast repetition rates, high degree of single photon purity, indistinguishability, and entanglement still impedes the practical applications. Semiconductor quantum dots are one of the leading system that have exhibited their potential for on-demand generation of high-quality single and entangled photon pairs for above applications. In this work, epitaxially grown III-V semiconductor quantum dots are investigated for driving their application in future quantum networks. First, an individual quantum dot emitting two pairs of entangled photons under pulsed two-photon resonant excitation has been utilized for realization of entanglement swapping, with the swapped photon pairs yielding a fidelity of 0.81 ± 0.04 to the Bell state Ψ+. To explore the practical limits of future quantum networks featuring multiple semiconductor based sources, we scrutinize the consequences of device fabrication, dynamic tuning techniques, time evolution of entanglement, and statistical effects on two separated quantum dot devices adapted in an entanglement swapping scheme. A numerical model based on the observed experimental data is proposed, serving not only as a benchmark for scalability of quantum dot devices, but also laying a roadmap for optimization of solid-state quantum emitters in quantum networks. For real-world quantum applications envisioned with quantum dots, the brightness of the quantum light sources is one of the key enabling factors, which is determined by the source excitation and extraction efficiency, as well as system detection system efficiency. Usually, the primary issue restricting the extraction of photons from III-V semiconductor quantum dots is the high-refractive index material of the host matrix which causes at the semiconductor-vacuum interface. To improve the photon extraction efficiency, a simple and efficient structure based on the principle of optical antennas is developed, resulting in an observed extraction of 17% of single photons in the telecom O-band, and a broadband enhancement of up to 180 times compared to the as-grown sample. A further limiting factor in the source efficiency is caused by the presence of charges in the solid-state environment. Charge fluctuation occur that quench radiative emission processes in resonant excitation schemes and induce fluorescence intermittence (blinking) that deteriorates the quantum yield. The photo-neutralization of GaAs/AlGaAs quantum dots excited by two-photon resonant pumping is investigated. Applying weak gate laser light to the quantum dot allows for controlling the charges capture processes. By adjusting the gate laser power and wavelength, an increase in excitation efficiency of 30% is observed compared to the two-photon resonant excitation without optical gating. The transition rates between the neutral and charged ground state are investigated by means of auto-/cross- correlation measurements. Furthermore, by studying a series of surface-passivated samples with different dot-to-surface distance as close to 20 nm, ODT was found to be an effective compound to neutralize the surface states, leading to reduced formation of non-radiative transition channels. It is anticipated that such a passivation method paves the way of near-field coupling related nano-photonic devices, or elimination of surface states for well-preserved emission properties towards the development of uncapped structure, fundamentally getting rid of total internal reflection to the maximum extent.European Research Council (ERC)/Starting Grant/QD-NOMS/E

    Distant Operational Care Centre: Design Project Report

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    The goal of this project is to outline the design of the Distant Operational Care Centre (DOCC), a modular medical facility to maintain human health and performance in space, that is adaptable to a range of remote human habitats. The purpose of this project is to outline a design, not to go into a complete technical specification of a medical facility for space. This project involves a process to produce a concise set of requirements, addressing the fundamental problems and issues regarding all aspects of a space medical facility for the future. The ideas presented here are at a high level, based on existing, researched, and hypothetical technologies. Given the long development times for space exploration, the outlined concepts from this project embodies a collection of identified problems, and corresponding proposed solutions and ideas, ready to contribute to future space exploration efforts. In order to provide a solid extrapolation and speculation in the context of the future of space medicine, the extent of this project's vision is roughly within the next two decades. The Distant Operational Care Centre (DOCC) is a modular medical facility for space. That is, its function is to maintain human health and performance in space environments, through prevention, diagnosis, and treatment. Furthermore, the DOCC must be adaptable to meet the environmental requirements of different remote human habitats, and support a high quality of human performance. To meet a diverse range of remote human habitats, the DOCC concentrates on a core medical capability that can then be adapted. Adaptation would make use of the DOCC's functional modularity, providing the ability to replace, add, and modify core functions of the DOCC by updating hardware, operations, and procedures. Some of the challenges to be addressed by this project include what constitutes the core medical capability in terms of hardware, operations, and procedures, and how DOCC can be adapted to different remote habitats

    ICTERI 2020: ІКТ в освіті, дослідженнях та промислових застосуваннях. Інтеграція, гармонізація та передача знань 2020: Матеріали 16-ї Міжнародної конференції. Том II: Семінари. Харків, Україна, 06-10 жовтня 2020 р.

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    This volume represents the proceedings of the Workshops co-located with the 16th International Conference on ICT in Education, Research, and Industrial Applications, held in Kharkiv, Ukraine, in October 2020. It comprises 101 contributed papers that were carefully peer-reviewed and selected from 233 submissions for the five workshops: RMSEBT, TheRMIT, ITER, 3L-Person, CoSinE, MROL. The volume is structured in six parts, each presenting the contributions for a particular workshop. The topical scope of the volume is aligned with the thematic tracks of ICTERI 2020: (I) Advances in ICT Research; (II) Information Systems: Technology and Applications; (III) Academia/Industry ICT Cooperation; and (IV) ICT in Education.Цей збірник представляє матеріали семінарів, які були проведені в рамках 16-ї Міжнародної конференції з ІКТ в освіті, наукових дослідженнях та промислових застосуваннях, що відбулася в Харкові, Україна, у жовтні 2020 року. Він містить 101 доповідь, які були ретельно рецензовані та відібрані з 233 заявок на участь у п'яти воркшопах: RMSEBT, TheRMIT, ITER, 3L-Person, CoSinE, MROL. Збірник складається з шести частин, кожна з яких представляє матеріали для певного семінару. Тематична спрямованість збірника узгоджена з тематичними напрямками ICTERI 2020: (I) Досягнення в галузі досліджень ІКТ; (II) Інформаційні системи: Технології і застосування; (ІІІ) Співпраця в галузі ІКТ між академічними і промисловими колами; і (IV) ІКТ в освіті

    CORPORATE SOCIAL RESPONSIBILITY IN ROMANIA

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    The purpose of this paper is to identify the main opportunities and limitations of corporate social responsibility (CSR). The survey was defined with the aim to involve the highest possible number of relevant CSR topics and give the issue a more wholesome perspective. It provides a basis for further comprehension and deeper analyses of specific CSR areas. The conditions determining the success of CSR in Romania have been defined in the paper on the basis of the previously cumulative knowledge as well as the results of various researches. This paper provides knowledge which may be useful in the programs promoting CSR.Corporate social responsibility, Supportive policies, Romania
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