Homomorphic System Research Articles

Sex chromosome evolution from a heteromorphic to a homomorphic system by inter-population hybridization in a frog.

Sex chromosomes generally evolve from a homomorphic to heteromorphic state. Once a heteromorphic system is established, the sex chromosome system may remain stable for an extended period. Here, we show the opposite case of sex chromosome evolution from a heteromorphic to a homomorphic system in the Japanese frog Glandirana rugosa. One geographic group, Neo-ZW, has ZZ-ZW type heteromorphic sex chromosomes. We found that its western edge populations, which are geographically close to another West-Japan group with homomorphic sex chromosomes of XX-XY type, showed homozygous genotypes of sex-linked genes in both sexes. Karyologically, no heteromorphic sex chromosomes were identified. Sex-reversal experiments revealed that the males were heterogametic in sex determination. In addition, we identified another similar population around at the southwestern edge of the Neo-ZW group in the Kii Peninsula: the frogs had homomorphic sex chromosomes under male heterogamety, while shared mitochondrial haplotypes with the XY group, which is located in the east and bears heteromorphic sex chromosomes. In conclusion, our study revealed that the heteromorphic sex chromosome systems independently reversed back to or turned over to a homomorphic system around each of the western and southwestern edges of the Neo-ZW group through hybridization with the West-Japan group bearing homomorphic sex chromosomes. This article is part of the theme issue 'Challenging the paradigm in sex chromosome evolution: empirical and theoretical insights with a focus on vertebrates (Part II)'.

Improved Cloud-Assisted Privacy-Preserving Profile-Matching Scheme in Mobile Social Networks

Due to the transparency of the wireless channel, users in multiple-key environment are vulnerable to eavesdropping during the process of uploading personal data and re-encryption keys. Besides, there is additional burden of key management arising from multiple keys of users. In addition, profile matching using inner product between vectors cannot effectively filter out users with ulterior motives. To tackle the above challenges, we first improve a homomorphic re-encryption system (HRES) to support a single homomorphic multiplication and arbitrarily many homomorphic additions. The public key negotiated by the clouds is used to encrypt the users’ data, thereby avoiding the issues of key leakage and key management, and the privacy of users’ data is also protected. Furthermore, our scheme utilizes the homomorphic multiplication property of the improved HRES algorithm to compute the cosine result between the normalized vectors as the standard for measuring the users’ proximity. Thus, we can effectively improve the social experience of users.

Increasing System Security with Full Homo-morphic Encryption using Lagrange’s Functions

Homo-morphic systems present a novel way to encrypt data, via which operations performed on the encrypted data are fully/partially reflected in the decrypted data. For example, if the input data D is homo-morphically encrypted to E, and if we perform X=E+N, then while decrypting X, we are bound to get D+N. Such a kind of encryption helps data owners to safely share their data among different analysers, without the risk of any kind of data leakages. Data analysers usually perform mathematical operations on the data which include addition, subtraction, multiplication and division. Homo-morphic systems which support addition & subtraction but do not support multiplication and division are termed as partially homo-morphic systems. While systems which support all the operations are termed as fully homo-morphic systems. In this paper, we have implemented a fully homo-morphic system based on Lagrange’s functions. These functions help in improving the overall security of the system by adding stochastics to the input data, which ensures that the same input data has different cipher text, and full homo-morphism is achieved. Security of overall system increased by 40% by using FHE.

A Proposed Fully Homomorphic for Securing Cloud Banking Data at Rest

Fully homomorphic encryption (FHE) reaped the importance and amazement of most researchers and followers in data encryption issues, as programs are allowed to perform arithmetic operations on encrypted data without decrypting it and obtain results similar to the effects of arithmetic operations on unencrypted data. The first (FHE) model was introduced by Craig Gentry in 2009, and it was just theoretical research, but later significant progress was made on it, this research offers FHE system based on directly of factoring big prime numbers which consider open problem now, The proposed scheme offers a fully homomorphic system for data encryption and stores it in encrypted form on the cloud based on a new algorithm that has been tried on a local cloud and compared with two previous encryption systems (RSA and Paillier) and shows us that this algorithm reduces the time of encryption and decryption by 5 times compared to other systems.

Public Key and Leveled Attributes Access Policy Oriented Fully Homomorphic Encryption Scheme

Fully homomorphic encryption (FHE) has been considered as significant transition of cryptography, a difficult aim which could answer the world's obstacles of security and trust. FHE is also considered among the golden solutions for achieving security in cloud computation, MPC, data banks, etc. FHE was conceptualised in 1978, but it took approximately three decades to invent the first credible construction of FHE. The research in this area erupted after Craig Gentry's construction of FHE in 2009. Considerable developments have been made in getting more practical and efficient solutions. In this paper, we have gathered the state of art information in this field through surveying various schemes. We proposed detailed construction of our fully homomorphic system. The security and correctness analysis for the proposed procedure along with the experimental results are also given in the paper.

Multiple Sensor Application Using Secure Data Aggregation

For wireless sensor networks, data aggregation scheme that reduces a large amount of transmission is the most practical technique. In previous studies, Homomorphic encryptions have been applied to conceal communication during aggregation such that enciphered data can be aggregated algebraically without decryption. Since aggregators collect data without decryption, adversaries are not able to forge aggregated results by compromising them. However, these schemes are not satisfy multi-application environments. Second, these schemes become insecure in case some sensor nodes are compromised. Third, these schemes do not provide secure counting; thus, they may suffer unauthorized aggregation attacks. The problem of present study entitled as “MULTIPLE SENSOR APPLICATION USING SECURE DATA AGGREGATION”. Therefore, a new concealed data aggregation scheme is proposed to extended from Homomorphic public encryption system. The proposed scheme has three contributions. First, it is designed for a multi-application environment. The base station extracts application-specific data from aggregated cipher texts. Next, it mitigates the impact of compromising attacks in single application environments. Finally, it degrades the damage from unauthorized aggregations. To prove the proposed scheme’s robustness and efficiency, we also conducted the comprehensive analyses and comparisons in the end. I also include the timer which is used to the base station can detect the attacker entering into the system and sends the indication message to sensor node.

Some Homomorphic Cryptosystems Based on Nonassociative Structures

A homomorphic encryption allows specific types of computations on ciphertext and generates an encrypted result that matches the result of operations performed on the plaintext. Some classic cryptosystems, e.g., RSA and ElGamal, allow homomorphic computation of only one operation. In 2009, C. Gentry suggested a model of a fully homomorphic algebraic system, i.e., a cryptosystem that supports both addition and multiplication operations. This cryptosystem is based on lattices. Later M. Dijk, C. Gentry, S. Halevi, and V. Vaikuntanathan suggested a fully homomorphic system based on integers. In a 2010 paper of A. V. Gribov, P. A. Zolotykh, and A. V. Mikhalev, a cryptosystem based on a quasigroup ring was constructed, developing an approach of S. K. Rososhek, and a homomorphic property of this system was investigated. An example of a quasigroup for which this system is homomorphic is given. Also a homomorphic property of the ElGamal cryptosystem based on a medial quasigroup is shown.

A Randomized Response Protocol Based on Homomorphic Encryption

The investigation which involves the respondents privacy is hard to ensure the information security. To rectify this problem, Based on Homomorphic Response Protocol (RRPBH), a novel protocol using homomorphic encrypted system is proposed in this paper. The RRPBH uses the Paillier encryption algorithm to encrypt respondents answer. Paillier algorithm has the good properties of additive homomorphism and mixed multiplicative homomorphism. We can effectively compute the sum of respondents answer with better privacy protection by this protocol.

Computationally fast techniques to reduce AWGN and speckle in videos

Fast schemes to reduce additive white Gaussian noise (AWGN) and speckle in videos are presented. The proposed schemes use a change detection technique to measure the interframe motion and carry out estimations in both the spatial and temporal directions of the video. In the case of AWGN reduction, the well-known edge adaptive Wiener filter is used to perform the spatial estimation. Two different filters to carry out temporal estimation are presented based on novel weighted scalar Kalman and weighted running average filters, respectively. These temporal estimators are applied on the spatial estimate to obtain the spatiotemporal estimate. A new method is then used to appropriately combine the spatial and spatiotemporal estimates in order to obtain the final estimate of the uncorrupted signal. To achieve speckle reduction, we use an unbiased homomorphic system that comprises an edge adaptive filter for spatial estimation and the weighted running average filter for temporal estimation. The effectiveness of the various proposed algorithms is demonstrated and compared with that of some of the existing schemes through extensive simulations. It is found that the use of a change detection technique, instead of the popularly used complex motion estimation and compensation technique, to measure the interframe motion results in a considerable reduction of processing time. The proposed schemes perform equally well or better than the existing schemes in reducing the noise in videos.

Unbiased homomorphic system and its application in reducing multiplicative noise

The problem of reducing the multiplicative noise corrupting a signal is discussed. A generalisation of the existing sampled function weighted order (SFWO) filter is proposed by relaxing the symmetry condition on the probability density function (PDF) of the noise. This generalised SFWO filter is then used within a homomorphic system to reduce the multiplicative noise. It is shown that the output from such a system is biased, and hence, a suitable bias compensation technique is suggested. An unbiased homomorphic system, whose design is based on the PDF of the corrupting multiplicative noise, is proposed to reduce the noise. Images generated by coherent imaging systems are always corrupted by speckle, a kind of multiplicative noise having a lognormal distribution. A filter called the mean median filter, to reduce additive white Gaussian noise, is first proposed and then used within the unbiased homomorphic system to reduce the speckle in images. The effectiveness of the various proposed algorithms is demonstrated and compared with that of some of the existing schemes through extensive simulations.

Isothermal VLE Measurements for Difluoromethane + Dimethyl Ether and an Evaluation of Hydrogen Bonding

Vapor−liquid equilibria (VLE) data for the difluoromethane (R32) + dimethyl ether (RE170) system were measured with the aim of completing our study of hydrogen bonding between hydrofluorocarbons (HFCs) and dimethyl ether. The measurements were taken in an apparatus based on a static analytical method at temperatures ranging between (258.15 and 293.15) K. The R32 + RE170 system shows a slight negative deviation from Raoult's law that is attributed to hydrogen bonding between RE170 and R32. This H bonding was estimated using the homomorphic concept. The physical interaction was represented by the difference between the excess Gibbs energy (gE) of R32 + RE170 and its corresponding homomorphic system, the R32 + propane (R290) system. The VLE data were reduced by means of the Carnahan−Starling−De Santis (CSD) equation of state (EoS) together with the classical mixing rule and then by means of the Redlich−Kwong−Soave (RKS) EoS, with the Huron−Vidal mixing rule, using the NRTL equation for gE at infinite pressur...

A fuzzy target recognition system with homomorphic invariant feature extraction

Abstract A target recognition system based on the concept of fuzzy set theory and homomorphic system is proposed. It involves automatic threshold selection, feature extraction, and classification. An optimal threshold is selected by the fuzzy risk criterion, i.e. to separate a given image into meaningful grey level classes under the assumption that the object and pixel grey level values are normally distributed. An edge measure for evaluating thresholding methods is also presented. When an image is segmented, a set of invariant features called mean, variance, skewness, and kurtosis, which are derived from the spectrum histogram of the target image, is calculated. The classification is then accomplished using the membership function of the feature space of an image and stored patterns. By simulation results, we find that the fuzzy risk thresholding achieves significant performance according to the uniformity and edge measures, and the fuzzy filter with the invariant features has good performance even in lo...

A modified homomorphic approach on invariant features of object images

A homomorphic system based approach for extracting invariant features of object images is proposed in this paper. By this approach, the statistical values such as mean, variance, skewness, and kurtosis are calculated from the Walsh-domain intensity histogram of the object image. It is found that the statistical characteristics of this histogram are invariant under different environments of the object image such as translation, rotation, scale change, illumination change, and noise corruption. Hence these values can be used as features of the object image and applied to check whether the object is locked on or not during the tracking phase in an image tracking system. By experimental results, we find that these features keep close or better performance compared with the well known invariant moments methods for TV or FILR images, respeectively.

An optimal design for a homomorphic deconvolution system

A precise expression for the deconvolved signal is derived by introducing the transmission factor, which is defined as the factor of the ratio of the deconvolved signal to the desired signal. An optimal deconvolution system is then defined as the system which minimizes the energy of the maximum distortion factor (=1-transmission factor). It is shown by numerical examples that the proposed system gives superior performance compared to the conventional. >

Object reconstruction from noisy holograms: Multiplicative noise model

A constrained iterative scheme has been applied to reconstruct an object from a multiplicative-noise-corrupted hologram. A multiplicative homomorphic system is used to model the noise in this iterative scheme. Convergence property holds. One-dimensional simulation results are shown.

Solving the attenuation problem in emission computed tomography using homomorphic filters

An approach to the attenuation problem in positron emission computed tomography (PET) is discussed. The underlying idea of the method, in which a homomorphic system and an iterative convolution backprojection algorithm are employed, is described. The use of these two algorithms in the new algorithm is discussed. Results obtained with the algorithms are judged acceptable, with the reconstructed images of many different phantoms tested seeming to converge after several iterations.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Error analysis of homomorphic system structures

Error analysis of homomorphic system structures

Obtaining the EEG envelope in real time: a practical method based on homomorphic filtering.

A thorough study of the amplitude modulation characteristics of the EEG tracings remains to be done. In this paper a digital system is built in a way that permits real time elicitation of the EEG envelope, with a low computational effort. The EEG signal is considered to be the product of a slow varying envelope and a fast bipolar oscillation. The signal is applied to the input of a multiplicative homomorphic system which produces the envelope as its low-pass output. This method may then be the first step in a systematic on-line envelope analysis.

All-optical homomorphic image-processing system

An optical homomorphic system obtained by the use of the halftone technique has been realized that involves the effective use of a logarithmic and an exponential contact screen. Logarithmic filtering alone is able to separate the multiplicative noise. But the application of exponential processing on the logarithmically operated image restores the image and completes the homomorphic system.

A method of automatic image reconstruction from holograms by a homomorphic system of logarithmic transform type

AbstractA new computer technique for automatic image reconstruction from holograms is proposed. The technique is based on the idea of filtering in a homomorphic system of the logarithmic‐transform type. The theoretical analysis and computer simulation were conducted using the proposed technique. The technique is based on the principle that the odd function of the phase term of the Fourier transform of a real‐number function representing an object can be separated from the even function of the phase term of the propagation function representing the wave propagation. Accordingly, in the proposed method of image reconstruction the image plane can be determined automatically with only the given hologram data, even if information on the distance parameter is not obtained in the holo‐gram recording stage. To simulate the proposed technique on a computer, data of a Fresnel‐transformed hologram of complex number were generated numerically, with the assumption that a plane object is illuminated by a plane wave and image reconstruction was conducted by separating the even function of the phase term of the object function from the propagation function to demonstrate the validity of the proposed method. The possibility of automatic image reconstruction and problems of the proposed technique are discussed and the conventional method is compared with the result of the computer simulation.