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- 2018
- Material decomposition
- Dual-energy LINAC
- Cargo Security Inspection System
- Optoelectronic Information Science and Engineering
- Korea Atomic Energy Research Institute
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Broad-Spectrum Tunable Photoluminescent Material Based on Cascade Fluorescence Resonance Energy Transfer between Three Fluorophores Encapsulated within the Self-Assembled Surfactant Systems
摘要： A broad spectrum tunable photoluminescent material with dual encryption based on a two-step Fluorescence Resonance Energy Transfer (FRET) between Pyrene (Py), Coumarin480 (Cou480) and Rhodamine6G (R6G) in micelles of SDS and bmimDS is presented. The phenomenon is achievable due to the encapsulation of the fluorophores within these micelles. The transfer of energy as FRET between the pair Py and Cou480 showed ON at 336 nm and OFF at 402 nm in contrast to the FRET observed between the pair Cou480 and R6G that showed ON at 402nm and OFF at 336 nm. However, the transfer of energy as FRET occurs from Py to R6G in the presence of Cou480 when excited at 336 nm, thereby making it a chain of three fluorophores with Cou480 acting as a relay fluorophore receiving energy from Py and transferring it to R6G. The different FRET scenarios between the three fluorophores in micelles provide a window for the generation of a matrix of colors, which occupies a significant 2D area in the chromaticity diagram, having potential applications in security printing. The different fluorophoric ratios generate different colors based on their individual photonic emissions and the FRET processes taking place between them. Writing tests were carried out using varied ratios of the fluorophores in the micellar systems producing different colored outputs under the UV light with insignificant visibility under the white light. We envision that this as-discovered three fluorophoric FRET system could form the basis for the future development of multi-FRET light-harvesting devices and anti-counterfeiting security inks based on much simpler non-covalent interaction aided encapsulation of the fluorophores within the self-assembled soft systems.
关键词： micelles,security printing,Rhodamine6G (R6G),SDS,Pyrene (Py),Coumarin480 (Cou480),bmimDS,Fluorescence Resonance Energy Transfer (FRET),photoluminescent material
更新于2025-11-19 16:46:39
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Scaling effects on the optical properties of patterned nano-layered shape memory films
摘要： Nano-layered films of PVAc/PU systems were fabricated by forced assembly coextrusion method. The bulk shape memory properties of PVAc/PU systems were utilized to program nanoscale patterns such as diffraction grating which exhibit iridescence after patterning. A hot embossing process has been utilized to imprint diffraction grating patterns as nano-scale information onto the surface of the thin multilayer films. Three levels of hierarchy i.e. layer thickness, spacing and heights of patterns, governs the functionality of the patterned multilayer film. The time and temperature dependent viscoelastic shape memory behavior determines the opto-mechanical tunability of the film. Mechanical switching of the patterns also leads to optical switching of the films which corresponds to their efficiency of information retrieval. The recovery of patterns as well as the diffractive property depends on the layer thickness (l) of films and heights of patterns (h0). The results illustrate that the higher ratio of h0/l better is the recovery of the grating patterns and the corresponding diffractive properties. This scaling effect enables versatile applications in information security by tuning the layer structure of the multilayer shape memory films.
关键词： scaling effect,shape memory film,pattern programming,hot embossing,multilayer film,information security,diffractive optical element,thermal responsive optics
更新于2025-10-22 19:40:53
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[IEEE 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Varna (2018.9.20-2018.9.22)] 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Influence investigation of the illumination on the quality indicators of the signal security activity
摘要： The publication represents the thesis that illumination is one of the important but often underestimated factors for the achievement of high quality signal security activities (SSA), especially in the part related to the efficient operation of the Mobile Security Patrol (MSP). Тhe speed of the MSP response, the possibilities of obtaining real information about the environment of the guarded object and the adequate counteraction of the intruders has been examined under the impact of the lightning. The risks of the process and the possibilities for its improvement at each step are examined and analyzed by applying a set of technical and organizational measures to ensure sufficient and reliable lightning. During the research is used simplified technology, that includes problems' visualization and the solutions are represented with a diagram and a table, which contributes to more clearly defined inconsistencies and corrective actions. The technology could be incorporated into the management systems of SSA as one of the means for improvement, according to the requirements of point 10 'Improvement', of management standards ISO 9001:2015, ISO 27001:2013, ISO 45001:2018 и ISO 18788:2015
关键词： signal security,risk,security,mobile security patrol,Lightning,quality
更新于2025-09-23 15:23:52
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Robust and Secure Image Fingerprinting Learned by Neural Network
摘要： Image ?ngerprinting is a technique that summarizes the perceptual characteristics of digital image into an invariant digest, and it is one of the most effective solutions for digital right management. Most conventional ?ngerprinting algorithms were developed by assembling manually designed feature extractor and quantizer, which requires extensive expert knowledge and may not capture the intrinsic or abstract visual characteristics of digital image. Focusing on content identi?cation related applications, we propose a data-driven image ?ngerprinting algorithm in this paper, where neural network is trained to automatically discover the optimal mapping from image to ?ngerprint. To ameliorate the dif?culty of training, we start by training the ?ngerprint-computation network in a layer-wise manner to progressively improve its robustness against content-preserving distortions. Initialized by the states learned by layer-wise training, the network is then re-trained as a holistic unit, with the objective of maximizing its content identi?cation accuracy. Moreover, we also develop a key-dependent version of the neural network based ?ngerprinting algorithm. By quantifying its security using information-theoretic metrics, we have proved that the hierarchical architecture of neural network is bene?cial to the security of ?ngerprinting algorithm. The experimental results on a large testing database show that the proposed work exhibits much higher content identi?cation accuracy than state-of-the-art algorithms, and its execution speed is in the millisecond time scale.
关键词： Content ?ngerprinting,Multimedia security,Content identi?cation,Image ?ngerprinting
更新于2025-09-23 15:23:52
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Quantum encryption and generalized Shannon impossibility
摘要： The famous Shannon impossibility result says that any encryption scheme with perfect secrecy requires a secret key at least as long as the message. In this paper we provide its quantum analogue with imperfect secrecy and imperfect correctness. We also give a systematic study of information-theoretically secure quantum encryption with two secrecy definitions. We show that the weaker one implies the stronger but with a security loss in d, where d is the dimension of the encrypted quantum system. This is good enough if the target secrecy error is of o(d?1).
关键词： Quantum one-time pad,Shannon impossibility,Information-theoretic security,Key length
更新于2025-09-23 15:23:52
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Cosine-transform-based chaotic system for image encryption
摘要： Chaos is known as a natural candidate for cryptography applications owing to its properties such as unpredictability and initial state sensitivity. However, certain chaos-based cryptosystems have been proven to exhibit various security defects because their used chaotic maps do not have complex dynamical behaviors. To address this problem, this paper introduces a cosine-transform-based chaotic system (CTBCS). Using two chaotic maps as seed maps, the CTBCS can produce chaotic maps with complex dynamical behaviors. For illustration, we produce three chaotic maps using the CTBCS and analyze their chaos complexity. Using one of the generated chaotic maps, we further propose an image encryption scheme. The encryption scheme uses high-efficiency scrambling to separate adjacent pixels and employs random order substitution to spread a small change in the plain-image to all pixels of the cipher-image. The performance evaluation demonstrates that the chaotic maps generated by the CTBCS exhibit substantially more complicated chaotic behaviors than the existing ones. The simulation results indicate the reliability of the proposed image encryption scheme. Moreover, the security analysis demonstrates that the proposed image encryption scheme provides a higher level of security than several advanced image encryption schemes.
关键词： Image privacy,Chaotic system,Image encryption,Cryptography,Security analysis,Chaos-based encryption
更新于2025-09-23 15:23:52
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[IEEE 2018 10th IAPR Workshop on Pattern Recognition in Remote Sensing (PRRS) - Beijing (2018.8.19-2018.8.20)] 2018 10th IAPR Workshop on Pattern Recognition in Remote Sensing (PRRS) - FPGA Optimization for Hyperspectral Target Detection with Collaborative Representation
摘要： Most applications based on wireless sensor networks (WSN) have devices with constraints of limited energy and computational/storage capabilities. The traditional security mechanisms are not desirable to these applications. A lightweight security and energy-efficient clustering protocol was proposed in this paper to solve the security problem in the clustering-based sensor networks. Firstly, a lightweight security algorithm is proposed to meet the security requirements, which reduces the communication overload by using the transmission key index. Secondly, in the process of clustering, the base station (BS) and cluster head (CH) use lightweight authentication procedure to verify the identities hierarchically, to reduce the risk of attacks from malicious nodes posing as BS or CH. Thirdly, the proposed protocol is analyzed in the aspects of security and energy consumption. Simulation results show that the proposed protocol not only enhances the network security but also improves the energy efficiency.
关键词： Lightweight security,Energy-efficient protocol,Clustering WSN
更新于2025-09-23 15:23:52
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One-out-of-two Quantum Oblivious Transfer based on Nonorthogonal States
摘要： This research proposes the first one-out-of-two quantum oblivious transfer (QOT) scheme that does not have a two-level structure and is not subject to Lo’s no-go theorem. Instead, the proposed scheme is a simple and efficient approach based on nonorthogonal states. The nonorthogonality causes one of a pair of messages to be unable to be measured to achieve the irreversible goal of discarding a message, resulting in a one-out-of-two selection effect. The proposed QOT protocol is therefore built directly on quantum resources rather than on a two-level structure in which two classical keys must first be created using quantum resources (all-or-nothing QOT) and then a one-out-of-two protocol is built from there. Furthermore, the proposed protocol allows Alice and Bob to test each other’s loyalty by comparing measurement results. In addition, the relationship with the no-go theorem is discussed in detail; this relationship is often overlooked in other studies. A security analysis demonstrates that the proposed protocol is secure against both external and internal attacks. In addition, an efficiency analysis shows that the proposed protocol is more efficient than other, two-level-structured protocols.
关键词： quantum oblivious transfer,security analysis,efficiency analysis,nonorthogonal states,Lo’s no-go theorem
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE 16th International Conference on Embedded and Ubiquitous Computing (EUC) - Bucharest, Romania (2018.10.29-2018.10.31)] 2018 IEEE 16th International Conference on Embedded and Ubiquitous Computing (EUC) - Android Fingerprint Sensor: Pitfalls and Challenges
摘要： In the last four years, the number of smartphones capable to read user fingerprints in order to perform authorization and authentication has tripled. Also, after the introduction of biometric payment services, fingerprint scanner driven authentication became more popular and the variety of smartphones equipped with this kind of sensor multiplied. However, the implementation methods are directly handled by manufacturers, who are often making decisions under the pressure of a short time-to-market. Starting from these facts, scholars and industry leading experts started to research the documentation in order to analyze the privacy and security flaws of the existing implementations. the assessment of Android good practice advises has revealed that some devices were not compliant, due to the fact that architecture could be attacked by an adversary both from the external world and by using malicious applications. Most common types of attacks against fingerprint authentication which could be demonstrated were aiming either to confuse the user in order to perform a malicious operation without a proper context or by employing custom-made molds of the user thumb minutiae. This paper analyses former and current issues affecting the fingerprint authentication in mobile devices powered by the Android operating system.
关键词： Android operating system,fingerprint sensor,security flaws
更新于2025-09-23 15:23:52
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Physical Layer Security of Hybrid Satellite-FSO Cooperative Systems
摘要： In this paper, we study the physical layer secrecy performance of a hybrid satellite and free-space optical (FSO) cooperative system. The satellite links are assumed to follow the Shadowed-Rician fading distribution; and the channel of the terrestrial link between the relay and destination is assumed to experience the Gamma-Gamma fading. For the FSO communications, the effects of different types of detection techniques (i.e., heterodyne detection and intensity modulation with direct detection) as well as the pointing error are considered. We derive exact analytical expressions for the average secrecy capacity (ASC) and secrecy outage probability (SOP) for both cases of Amplify-and-Forward (AF) and Decode-and-Forward (DF) relaying. The asymptotic analysis for the SOP is also conducted to provide more insights on the impact of FSO and satellite channels on secrecy performance. It is found that with the AF with fixed gain scheme, the secrecy diversity order of the investigated system is only dependent on the channel characteristics of the FSO link and the FSO detection type, whereas the secrecy diversity is zero when the relay node employs DF or AF with variable-gain schemes.
关键词： land mobile satellite (LMS) channel,secrecy outage probability,hybrid satellite free-space optical (FSO) cooperative system,Physical layer security,average secrecy capacity
更新于2025-09-23 15:22:29