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Symmetry, Volume 7, Issue 1 (March 2015) – 19 articles , Pages 1-283

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832 KiB  
Technical Note
Study on User Authority Management for Safe Data Protection in Cloud Computing Environments
by Su-Hyun Kim and Im-Yeong Lee
Symmetry 2015, 7(1), 269-283; https://doi.org/10.3390/sym7010269 - 19 Mar 2015
Cited by 9 | Viewed by 5808
Abstract
In cloud computing environments, user data are encrypted using numerous distributed servers before storing such data. Global Internet service companies, such as Google and Yahoo, recognized the importance of Internet service platforms and conducted self-research and development to create and utilize large cluster-based [...] Read more.
In cloud computing environments, user data are encrypted using numerous distributed servers before storing such data. Global Internet service companies, such as Google and Yahoo, recognized the importance of Internet service platforms and conducted self-research and development to create and utilize large cluster-based cloud computing platform technology based on low-priced commercial nodes. As diverse data services become possible in distributed computing environments, high-capacity distributed management is emerging as a major issue. Meanwhile, because of the diverse forms of using high-capacity data, security vulnerability and privacy invasion by malicious attackers or internal users can occur. As such, when various sensitive data are stored in cloud servers and used from there, the problem of data spill might occur because of external attackers or the poor management of internal users. Data can be managed through encryption to prevent such problems. However, existing simple encryption methods involve problems associated with the management of access to data stored in cloud environments. Therefore, in the present paper, a technique for data access management by user authority, based on Attribute-Based Encryption (ABE) and secret distribution techniques, is proposed. Full article
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1427 KiB  
Article
Fluctuating Asymmetry of Plant Leaves: Batch Processing with LAMINA and Continuous Symmetry Measures
by John H. Graham, Mattie J. Whitesell, Mark Fleming II, Hagit Hel-Or, Eviatar Nevo and Shmuel Raz
Symmetry 2015, 7(1), 255-268; https://doi.org/10.3390/sym7010255 - 13 Mar 2015
Cited by 17 | Viewed by 11507
Abstract
Unlike landmark methods for estimating object asymmetry, continuous symmetry measures (CSM) can be used to measure the symmetry distance (ds) of inconsistent objects, such as plant leaves. Inconsistent objects have no homologous landmarks, no consistent topology, no quantitative consistency, and [...] Read more.
Unlike landmark methods for estimating object asymmetry, continuous symmetry measures (CSM) can be used to measure the symmetry distance (ds) of inconsistent objects, such as plant leaves. Inconsistent objects have no homologous landmarks, no consistent topology, no quantitative consistency, and sometimes no matching points. When CSM is used in conjugation with LAMINA Leaf Shape Determination software, one can quickly and efficiently process a large number of scanned leaves. LAMINA automatically generates equally-spaced points around the perimeter of each leaf and the resulting x-y coordinates are normalized to average centroid size prior to estimating ds using a fold, average, unfold algorithm. We estimated shape asymmetry of leaves of three species of flowering plants: Ligustrum sinense (Chinese Privet), Rubus cuneifolius (blackberry), and Perilla frutescens (Perilla), as well as individual leaves from a few species of oaks (Quercus) and maples (Acer). We found that 100 to 200 equally-spaced points worked well for all three of the main species. Measurement error accounted for a small proportion of the asymmetry variation. Nevertheless, measurement error was great enough to generate some negative size scaling after normalization to average centroid size. Full article
(This article belongs to the Special Issue Fluctuating Asymmetry)
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741 KiB  
Article
Evidence for Obliqueness of Angles as a Cue to Planar Surface Slant Found in Extremely Simple Symmetrical Shapes
by Casper J. Erkelens
Symmetry 2015, 7(1), 241-254; https://doi.org/10.3390/sym7010241 - 09 Mar 2015
Cited by 4 | Viewed by 6052
Abstract
The Necker cube is a striking example for perceptual dominance of 3D over 2D. Object symmetry and obliqueness of angles are co-varying cues that may underlie the perceived slant of Necker cubes. To investigate the power of the oblique-angle cue, slants were judged [...] Read more.
The Necker cube is a striking example for perceptual dominance of 3D over 2D. Object symmetry and obliqueness of angles are co-varying cues that may underlie the perceived slant of Necker cubes. To investigate the power of the oblique-angle cue, slants were judged of extremely simple symmetrical shapes. Slant computations based on an assumption of orthogonality were made for two abutting lines as a function of vertex angle and the slant of the screen. Computed slants were compared with slants judged by six subjects under binocular viewing conditions. Judged slant was highly correlated with slant specified by the oblique angles under an assumption of orthogonality. The contributions of screen cues, including binocular disparity, were negligible. The consistency of the judgments across subjects indicates the assumption of orthogonality as one of the principles underlying slant perception. Necker cubes illustrate that the visual system can disengage unambiguous cues in favor of ambiguous object-symmetry and oblique-angle cues, if the latter indicate very different slants. Selective disengagement of cues may be the mechanism that underlies the success of 2D images in ancient, as well as modern civilizations. Full article
(This article belongs to the Special Issue Symmetry: Theory and Applications in Vision)
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285 KiB  
Review
Inflationary Cosmology in Modified Gravity Theories
by Kazuharu Bamba and Sergei D. Odintsov
Symmetry 2015, 7(1), 220-240; https://doi.org/10.3390/sym7010220 - 09 Mar 2015
Cited by 285 | Viewed by 8557
Abstract
We review inflationary cosmology in modified gravity such as R2 gravity with its extensions in order to generalize the Starobinsky inflation model. In particular, we explore inflation realized by three kinds of effects: modification of gravity, the quantum anomaly, and the R [...] Read more.
We review inflationary cosmology in modified gravity such as R2 gravity with its extensions in order to generalize the Starobinsky inflation model. In particular, we explore inflation realized by three kinds of effects: modification of gravity, the quantum anomaly, and the R2 term in loop quantum cosmology. It is explicitly demonstrated that in these inflationary models, the spectral index of scalar modes of the density perturbations and the tensor-to-scalar ratio can be consistent with the Planck results. Bounce cosmology in F(R) gravity is also explained. Full article
676 KiB  
Article
Teaching-Learning Activity Modeling Based on Data Analysis
by Kyungrog Kim, Yoo-Joo Choi, Mihui Kim, Jung-Won Lee, Doo-Soon Park and Nammee Moon
Symmetry 2015, 7(1), 206-219; https://doi.org/10.3390/sym7010206 - 05 Mar 2015
Cited by 6 | Viewed by 6006
Abstract
Numerous studies are currently being carried out on personalized services based on data analysis to find and provide valuable information about information overload. Furthermore, the number of studies on data analysis of teaching-learning activities for personalized services in the field of teaching-learning is [...] Read more.
Numerous studies are currently being carried out on personalized services based on data analysis to find and provide valuable information about information overload. Furthermore, the number of studies on data analysis of teaching-learning activities for personalized services in the field of teaching-learning is increasing, too. This paper proposes a learning style recency-frequency-durability (LS-RFD) model for quantified analysis on the level of activities of learners, to provide the elements of teaching-learning activities according to the learning style of the learner among various parameters for personalized service. This is to measure preferences as to teaching-learning activity according to recency, frequency and durability of such activities. Based on the results, user characteristics can be classified into groups for teaching-learning activity by categorizing the level of preference and activity of the learner. Full article
(This article belongs to the Special Issue Advanced Symmetry Modelling and Services in Future IT Environments)
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247 KiB  
Article
126 GeV Higgs Boson Associated with D-term Triggered Dynamical Supersymmetry Breaking
by Hiroshi Itoyama and Nobuhito Maru
Symmetry 2015, 7(1), 193-205; https://doi.org/10.3390/sym7010193 - 03 Mar 2015
Cited by 17 | Viewed by 5030
Abstract
Continuing with our previous work on \(D\)-term triggered dynamical supersymmetry breaking, , we consider a system in which our generic \({\cal N}=1\) action is minimally extended to include the pair of Higgs doublet superfields charged under the overall \(U(1)\) together with μ and [...] Read more.
Continuing with our previous work on \(D\)-term triggered dynamical supersymmetry breaking, , we consider a system in which our generic \({\cal N}=1\) action is minimally extended to include the pair of Higgs doublet superfields charged under the overall \(U(1)\) together with μ and Bμ terms. The gauge group is taken to be \(SU(3)_C \times SU(2)_L \times U(1)_Y \times U(1)\). We point out, among other things, that the Higgs mass less than the \(\textit{Z}\)-boson mass at tree level can be pushed up to be around 126 GeV by \(D\)-term contributions of the overall \(U(1)\). This is readily realized by taking a \(U(1)\) gauge coupling to be \({\cal O}(1)\). Full article
(This article belongs to the Special Issue Supersymmetry 2014)
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27304 KiB  
Article
Real-Time Projection-Based Augmented Reality System for Dynamic Objects in the Performing Arts
by Jaewoon Lee, Yeonjin Kim, Myeong-Hyeon Heo, Dongho Kim and Byeong-Seok Shin
Symmetry 2015, 7(1), 182-192; https://doi.org/10.3390/sym7010182 - 27 Feb 2015
Cited by 19 | Viewed by 17623
Abstract
This paper describes the case study of applying projection-based augmented reality, especially for dynamic objects in live performing shows, such as plays, dancing, or musicals. Our study aims to project imagery correctly inside the silhouettes of flexible objects, in other words, live actors [...] Read more.
This paper describes the case study of applying projection-based augmented reality, especially for dynamic objects in live performing shows, such as plays, dancing, or musicals. Our study aims to project imagery correctly inside the silhouettes of flexible objects, in other words, live actors or the surface of actor’s costumes; the silhouette transforms its own shape frequently. To realize this work, we implemented a special projection system based on the real-time masking technique, that is to say real-time projection-based augmented reality system for dynamic objects in performing arts. We installed the sets on a stage for live performance, and rehearsed particular scenes of a musical. In live performance, using projection-based augmented reality technology enhances technical and theatrical aspects which were not possible with existing video projection techniques. The projected images on the surfaces of actor’s costume could not only express the particular scene of a performance more effectively, but also lead the audience to an extraordinary visual experience. Full article
(This article belongs to the Special Issue Advanced Symmetry Modelling and Services in Future IT Environments)
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73625 KiB  
Article
Symmetry of “Twins”
by Vladan Nikolić, Ljiljana Radović and Biserka Marković
Symmetry 2015, 7(1), 164-181; https://doi.org/10.3390/sym7010164 - 13 Feb 2015
Cited by 4 | Viewed by 14072
Abstract
The idea of construction of twin buildings is as old as architecture itself, and yet there is hardly any study emphasizing their specificity. Most frequently there are two objects or elements in an architectural composition of “twins” in which there may be various [...] Read more.
The idea of construction of twin buildings is as old as architecture itself, and yet there is hardly any study emphasizing their specificity. Most frequently there are two objects or elements in an architectural composition of “twins” in which there may be various symmetry relations, mostly bilateral symmetries. The classification of “twins” symmetry in this paper is based on the existence of bilateral symmetry, in terms of the perception of an observer. The classification includes both, 2D and 3D perception analyses. We start analyzing a pair of twin buildings with projection of the architectural composition elements in 2D picture plane (plane of the composition) and we distinguish four 2D keyframe cases based on the relation between the bilateral symmetry of the twin composition and the bilateral symmetry of each element. In 3D perception for each 2D keyframe case there are two sub-variants, with and without a symmetry plane parallel to the picture plane. The bilateral symmetry is dominant if the corresponding symmetry plane is orthogonal to the picture plane. The essence of the complete classification is relation between the bilateral (dominant) symmetry of the architectural composition and the bilateral symmetry of each element of that composition. Full article
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10569 KiB  
Article
The Genetic Architecture of Fluctuating Asymmetry of Mandible Size and Shape in a Population of Mice: Another Look
by Larry J. Leamy, Christian Peter Klingenberg, Emma Sherratt, Jason B. Wolf and James M. Cheverud
Symmetry 2015, 7(1), 146-163; https://doi.org/10.3390/sym7010146 - 11 Feb 2015
Cited by 21 | Viewed by 6742
Abstract
Fluctuating asymmetry (FA), typically measured by variation in the differences between right and left sides of bilateral traits, is commonly used to assess developmental instability (DI) in populations. A previous quantitative trait locus (QTL) investigation using an F2 intercross mouse population found [...] Read more.
Fluctuating asymmetry (FA), typically measured by variation in the differences between right and left sides of bilateral traits, is commonly used to assess developmental instability (DI) in populations. A previous quantitative trait locus (QTL) investigation using an F2 intercross mouse population found little evidence of individual loci affecting FA in mandible size, but an abundance of epistatic interactions between loci. Here we extend this work by testing whether these patterns replicate in an F3 population derived from the same intercross. Using a large number of molecular markers genotyped in over 1200 mice, we uncovered significant interactions between loci (QTLs) affecting FA in mandible size (and shape). Epistasis contributed roughly 20% of the variation in FASIZE and 19% of the variation in FASHAPE at the 0.0001 probability level alone, and was comparable to that previously estimated for the F2 mice, and much greater than that generated from the few single-locus QTLs affecting the mandible FA traits. The positions of the single-locus and epistatic QTLs for FA that we discovered suggested that logical candidate genes for DI are those controlling size or shape in the traits themselves, and that they may be interacting with genes for heat shock proteins. Full article
(This article belongs to the Special Issue Fluctuating Asymmetry)
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3800 KiB  
Article
Crystallography and Magnetic Phenomena
by Vojtěch Kopský
Symmetry 2015, 7(1), 125-145; https://doi.org/10.3390/sym7010125 - 02 Feb 2015
Cited by 5 | Viewed by 6569
Abstract
This essay describes the development of groups used for the specification of symmetries from ordinary and magnetic point groups to Fedorov and magnetic space groups, as well as other varieties of groups useful in the study of symmetric objects. In particular, we consider [...] Read more.
This essay describes the development of groups used for the specification of symmetries from ordinary and magnetic point groups to Fedorov and magnetic space groups, as well as other varieties of groups useful in the study of symmetric objects. In particular, we consider the problem of some incorrectness in Vol. A of the International Tables for Crystallography. Some results of tensor calculus are presented in connection with magnetoelectric phenomena, where we demonstrate the use of Ascher’s trinities and Opechowski’s magic relations and their connection. Specific tensor decomposition calculations on the grounds of Clebsch Gordan products are illustrated. Full article
(This article belongs to the Special Issue Crystal Symmetry and Structure)
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357 KiB  
Article
Two-Round Password-Only Authenticated Key Exchange in the Three-Party Setting
by Junghyun Nam, Kim-Kwang Raymond Choo, Sangchul Han, Juryon Paik and Dongho Won
Symmetry 2015, 7(1), 105-124; https://doi.org/10.3390/sym7010105 - 27 Jan 2015
Cited by 11 | Viewed by 6071
Abstract
We present the first provably-secure three-party password-only authenticated key exchange (PAKE) protocol that can run in only two communication rounds. Our protocol is generic in the sense that it can be constructed from any two-party PAKE protocol. The protocol is proven secure in [...] Read more.
We present the first provably-secure three-party password-only authenticated key exchange (PAKE) protocol that can run in only two communication rounds. Our protocol is generic in the sense that it can be constructed from any two-party PAKE protocol. The protocol is proven secure in a variant of the widely-accepted model of Bellare, Pointcheval and Rogaway (2000) without any idealized assumptions on the cryptographic primitives used. We also investigate the security of the two-round, three-party PAKE protocol of Wang, Hu and Li (2010) and demonstrate that this protocol cannot achieve implicit key authentication in the presence of an active adversary. Full article
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7044 KiB  
Article
Can the Comparisons of Feature Locations Explain the Difficulty in Discriminating Mirror-Reflected Pairs of Geometrical Figures from Disoriented Identical Pairs?
by Fumio Kanbe
Symmetry 2015, 7(1), 89-104; https://doi.org/10.3390/sym7010089 - 23 Jan 2015
Cited by 4 | Viewed by 5002
Abstract
The present experiment investigates whether patterns of shifts of feature locations could affect the same/different decisions of simultaneously presented pairs of geometrical figures. A shift of locations was defined as the angular distance from the location of a feature in one figure to [...] Read more.
The present experiment investigates whether patterns of shifts of feature locations could affect the same/different decisions of simultaneously presented pairs of geometrical figures. A shift of locations was defined as the angular distance from the location of a feature in one figure to the location of the same feature in another figure. It was hypothesized that the difficulty in discriminating mirror-reflected (or axisymmetric) pairs from disoriented identical pairs was caused by complex shifting patterns inherent in axisymmetric pairs. According to the shifts of the locations of the four structural features, five pair types were prepared. They could be ordered from completely identical to completely different in their shifts: identical 0/4 pairs, non-identical 1/4 pairs, non-identical 2/4 pairs = axisymmetric 2/4 pairs and non-identical 4/4 pairs. The latencies for non-identical pairs decreased with the increase of difference in the shifts of feature locations, indicating that serial, self-terminating comparisons of the shifts were applied to the discrimination of non-identical pairs from identical pairs. However, the longer latencies in axisymmetric 2/4 pairs than in non-identical 2/4 pairs suggested that the difficulty for axisymmetric pairs was not caused by the complex shifting patterns, and the difficulty was not satisfactorily explained by the comparisons of feature locations. Full article
(This article belongs to the Special Issue Visual Symmetry)
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336 KiB  
Article
Dihedral Reductions of Cyclic DNA Sequences
by Marlos A.G. Viana
Symmetry 2015, 7(1), 67-88; https://doi.org/10.3390/sym7010067 - 16 Jan 2015
Viewed by 4286
Abstract
The data-analytic methodology of dihedral reductions for cyclic orbits of distinct-base codons is described both in terms of Fourier analysis over the dihedral groups and in (algebraically equivalent) terms of canonical projections. Numerical evaluations are presented for discrete and continuous scalar data indexed [...] Read more.
The data-analytic methodology of dihedral reductions for cyclic orbits of distinct-base codons is described both in terms of Fourier analysis over the dihedral groups and in (algebraically equivalent) terms of canonical projections. Numerical evaluations are presented for discrete and continuous scalar data indexed by cyclic orbits. Full article
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550 KiB  
Article
Output Effect Evaluation Based on Input Features in Neural Incremental Attribute Learning for Better Classification Performance
by Ting Wang, Sheng-Uei Guan, Ka Lok Man, Jong Hyuk Park and Hui-Huang Hsu
Symmetry 2015, 7(1), 53-66; https://doi.org/10.3390/sym7010053 - 14 Jan 2015
Cited by 1 | Viewed by 4910
Abstract
Machine learning is a very important approach to pattern classification. This paper provides a better insight into Incremental Attribute Learning (IAL) with further analysis as to why it can exhibit better performance than conventional batch training. IAL is a novel supervised machine learning [...] Read more.
Machine learning is a very important approach to pattern classification. This paper provides a better insight into Incremental Attribute Learning (IAL) with further analysis as to why it can exhibit better performance than conventional batch training. IAL is a novel supervised machine learning strategy, which gradually trains features in one or more chunks. Previous research showed that IAL can obtain lower classification error rates than a conventional batch training approach. Yet the reason for that is still not very clear. In this study, the feasibility of IAL is verified by mathematical approaches. Moreover, experimental results derived by IAL neural networks on benchmarks also confirm the mathematical validation. Full article
(This article belongs to the Special Issue Advanced Symmetry Modelling and Services in Future IT Environments)
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705 KiB  
Article
Development of Guanidine-Bisurea Bifunctional Organocatalyst Bearing Chirality at the Inner and Outer Sides of the Urea Groups, and Application to Enantioselective α-Hydroxylation of Pyranoindolizine Intermediate for Camptothecin Synthesis
by Minami Odagi, Tatsuya Watanabe and Kazuo Nagasawa
Symmetry 2015, 7(1), 43-52; https://doi.org/10.3390/sym7010043 - 14 Jan 2015
Cited by 3 | Viewed by 5302
Abstract
Pyranoindolizine is a tricyclic structure found in various biologically active compounds, such as camptothecin (CPT) and its derivatives. In the case of CPTs, the chirality at the α-position in the α-hydroxyl lactone moiety of pyranoindolizine is important for the antitumor activity. This paper [...] Read more.
Pyranoindolizine is a tricyclic structure found in various biologically active compounds, such as camptothecin (CPT) and its derivatives. In the case of CPTs, the chirality at the α-position in the α-hydroxyl lactone moiety of pyranoindolizine is important for the antitumor activity. This paper deals with enantioselective oxidation of the α-position in pyranoindolizine lactone, which corresponds at C20 in CPT, with cumene hydroperoxide (CHP) in the presence of newly synthesized guanidine-bisurea bifunctional organocatalysts bearing chirality on both the inner and outer sides of the urea groups. Full article
(This article belongs to the Special Issue Asymmetric Catalysis)
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249 KiB  
Editorial
Acknowledgement to Reviewers of Symmetry in 2014
by Symmetry Editorial Office
Symmetry 2015, 7(1), 40-42; https://doi.org/10.3390/sym7010040 - 07 Jan 2015
Viewed by 3512
Abstract
The editors of Symmetry would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2014:[...] Full article
15369 KiB  
Article
Topology and the Visualization of Space
by Tony Robbin
Symmetry 2015, 7(1), 32-39; https://doi.org/10.3390/sym7010032 - 30 Dec 2014
Cited by 4 | Viewed by 6444
Abstract
Overlapping patterns provide the diagrammatics for four-dimensional space. If these patterns are three-dimensional lattices, and if one imagines them extended in three-dimensional space, then the diagram makes a model of physical space. Full article
(This article belongs to the Special Issue Diagrams, Topology, Categories and Logic)
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417 KiB  
Article
Effect of Tensor Correlations on the Density Dependence of the Nuclear Symmetry Energy
by Isaac Vidaña, Constança Providência and Artur Polls
Symmetry 2015, 7(1), 15-31; https://doi.org/10.3390/sym7010015 - 29 Dec 2014
Cited by 2 | Viewed by 4538
Abstract
We analyze the effect of the tensor force and other components of the nucleon-nucleon interaction on the nuclear symmetry energy and its density dependence by using the Hellmann–Feynman theorem. The analysis is performed within the microscopic Brueckner–Hartree–Fock approach using the Argonne V18 potential [...] Read more.
We analyze the effect of the tensor force and other components of the nucleon-nucleon interaction on the nuclear symmetry energy and its density dependence by using the Hellmann–Feynman theorem. The analysis is performed within the microscopic Brueckner–Hartree–Fock approach using the Argonne V18 potential plus a Urbana IX three-nucleon force. Our results show that the potential part of the nuclear Hamiltonian, and in particular its tensor component, gives the largest contribution to the symmetry energy. The decomposition of the symmetry energy into a kinetic part and a potential energy part provides physical insight on the correlated nature of the system, indicating that pure neutron matter is less correlated than symmetric nuclear matter. Full article
(This article belongs to the Special Issue Nuclear Symmetry Energy)
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616 KiB  
Article
A Study on Electronic-Money Technology Using Near Field Communication
by Min Soo Jung
Symmetry 2015, 7(1), 1-14; https://doi.org/10.3390/sym7010001 - 26 Dec 2014
Cited by 5 | Viewed by 6485
Abstract
Recently, due to the introduction of NFC (Near Field Communication), it has become possible to make easy electronic payments. Therefore, a secure communication method is necessary in these environments. NFC can be said to be relatively safe compared to other communication methods, because [...] Read more.
Recently, due to the introduction of NFC (Near Field Communication), it has become possible to make easy electronic payments. Therefore, a secure communication method is necessary in these environments. NFC can be said to be relatively safe compared to other communication methods, because it carries out communications within 10 cm. However, it has made possible the risk of impersonation attacks by a disguised reader, leaving user information on the reader. In order to solve these problems, in this paper, we propose an authentication scheme that can reduce the weight of computation by using only a hash function and XOR (eXclusive OR) operation algorithms. This paper also shows that our method is safe, since it leaves no information with the other party. Full article
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