An field programmable gate array implementation of an image encryption algorithm based on a discrete chaotic map

Software encryption cannot satisfy real time requirements for multimedia applications which usually involve large volumes of data. To address this problem, an field programmable gate array(FPGA) implementation of the Cyclone EP1C6 for a Kolmogorov chaotic map based image encryption algorithm MASK was proposed. The algorithm was composed of four basic parts: Mixture, key Add, S box and Kolmogorov chaotic map transforms. These parts specifically act on the image as follows: diffusion, applying secret keys, nonlinearity, and permutation. The correlation of adjacent pixels, UACI and the key space of the system subsequently were studied. The source occupation proportion of the hardware was calculated statistically and showed low occupation. Among the advantages of the proposed system are high security, fast encryption speed, and low hardware resources consumption. The proposed system is suitable for implementation in inexpensive FPGA.     

Construction of substitution boxes based on tangent delay ellipse reflecting cavity mapping system

Based on the good chaotic properties of tangent delay ellipse reflecting cavity mapping system (TD ERCS), a kind of novel substitution boxes were constructed. The cryptographic properties, such as bijection, nonlinearity, strict avalanche, independence of output bits, the differential approximation probability and the nonlinear approximation probability of the S box are analyzed. The investigation method for the strength of the S box with the discrete chaotic system proposed by Kocarev is discussed. Theoretical analysis and backtesting results show that the method is efficient and easy to put into practice, while the constructed S boxes show better cryptographic properties than the S boxes based on other chaotic system, which can be used to improve the existing encryption scheme.     

随机区间置换的安全算术编码及应用

基于压缩编码的加密方式能够同时完成加密和压缩的功能,通过压缩减少了信息的冗余,同时引入加密使对试图推测出明文信息和找到密钥的攻击具有非常好的鲁棒性。提出了一种基于随机区间置换的安全算术编码,在编码过程中通过随机密钥保证图像压缩编码的安全性,且不影响编码的效率,使其方便在网络中安全传输。实验结果和安全性分析表明该安全算术编码有较好的安全性和加密效率。     

Logistic map controlled secure arithmetic coding and its application in image encryption

A logistic map controlled secure arithmetic coding is proposed, the Logistic map is used to control the order of the symbols in the model and change the probabilities of the symbols, which is applied to the image encryption. The proposed scheme makes the image transmit more secure and comfortably on the Internet, and that is done at little expense in terms of coding efficiency. In the coding process, it ensures the uniformity of the model being changed by the chaotic sequence, thus to meet the security requirements of image compression. The algorithm can be applied to any arithmetic codec based on multimedia data including video, image and audio. Its most strength compared with other cipher mode is that, there is a significant reduction in the redundancy of information during the compression process, and it is robust when attempting to estimate the information of the image and discovering the key. The scheme can effectively resist differential analyses from both cryptography and coding.     

Realizing Key Schedule of Rijndael Algorithm Integrating with Chaos

Encryption is an important method which is used to protect the information of an individual and enterprises and the secret of nations. Rijndael algorithm is the new advanced encryption standard, and has extensive application foreground because of its much merit. Modem encryption algorithms are based on keys. However, so far few of people research into the key schedule of rijndael algorithm and especially do research on the generation of its initial keys. This paper researches into the mapping of Logistic, makes use of a chaos algorithm to produce initial encryption keys because it can create chaos sequences of high randomicity. Further more, corresponding CPLD implementation is given.     

Design and Implementation of Chaos Encrytion Algorithm based on Logistic Formula

The security of stream cipher, which is known as one of the main cipher techniques, dependents completely on the quality of generated pseudo-stochastic sequences. Chaotic systems can produce the pseudo-stochastic sequences with the properties of excessive dependence on initial conditions and the difficulty in forecasting, therefore, these systems are suitable to the stream cipher. A new encryption algorithm is proposed by analyzing the principle of the chaos encryption algorithm based on logistic formula. Moreover, the security and performance of the proposed algorithm is also estimated. Finally, an example is given to demonstrate our method via the Visual C++.     

Chaotic Time Series Analysis Based on Radial Basis Function Networks

A method based on radial basis function networks for forecasting chaotic time series is proposed.The nonlinear time series identification problem is formulated with a nonlinear autoregressive moving average(NARMAX)model then a new identification algorithm based on dynamic radial basis function networks is proposed.Then this method is applied to the estimation of embedding dimension for chaotic time series of Henon mapping and the confirmation of the chaotic phenomena in stock markets of China,from which one can get the desired results.Further research directions are also pointed out.     

An algorithm of image processing based on discrete wavelet transform compression and chaotic scrambling

An algorithm was proposed in view of the combination of image compression and encryption. We got the approximate part and three detail parts after transforming the image with discrete wavelet transform (DWT), and compressed the image by modifying the detail parts by a given threshold value based on human visual systems. And then, we encrypted the image by scrambling the approximate part because this part held mostly of the energy. Last, a compressed and encrypted image can be achieved after DWT. Simulation result shows a good effect on the combination of compression and encryption.     

Challenges to design-oriented breeding of root system architecture adapted to climate change

Roots are essential organs for capturing water and nutrients from the soil. In particular, root system architecture (RSA) determines the extent of the region of the soil where water and nutrients can be gathered. As global climate change accelerates, it will be important to improve belowground plant parts, as well as aboveground ones, because roots are front-line organs in the response to abiotic stresses such as drought, flooding, and salinity stress. However, using conventional breeding based on phenotypic selection, it is difficult to select breeding lines possessing promising RSAs to adapted to abiotic stress because roots remain hidden underground. Therefore, new breeding strategies that do not require phenotypic selection are necessary. Recent advances in molecular biology and biotechnology can be applied to the design-oriented breeding of RSA without phenotypic selection. Here I summarize recent progress in RSA ideotypes as “design” and RSA-related gene resources as “materials” that will be needed in leveraging these technologies for the RSA breeding. I also highlight the future challenges to design-oriented breeding of RSA and explore solutions to these challenges.     

Robust adaptive control for nonlinear chaotic systems

Tracking control of a nonlinear uncertain Chua's chaotic system is studied. With coordinate transform, Chua's chaotic system is transformed to a general form of a strict feedback control system. Combining the backstepping method with robust control technology, an adaptive parameter control law for a robust output feedback control scheme is developed for output tracking of nonlinear unknown systems. It is shown that the derived robust adaptive controller based on Lyapunov stability theory can guarantee global uniformly bounded ultimate property for all states of the closed loop system, and lead to tracking error decreasing at exponential speed. The simulation results show the effectiveness of the proposed approach.     

The frequency detection model with anti-noise in the autonomous chaotic system

A method of detecting the signal frequency which is disturbed by the noise based on the autonomous chaotic system is proposed. A signal with noise was added to an autonomous chaotic system, and then a negative feedback was imposed to it. The feedback gain was appropriately adjusted, so as to let the noisy system orbit be a limit cycle. The number of times that the orbit went directly through a plane was calculated by loop phase technology, and the vibration frequency was found according to it. The frequency of system is determined by the frequency of the test signal, yet free from noise, so the frequency of the test signal is the vibration frequency of the system. Simulation results further demonstrate the effectiveness of the method.     

Improving the efficiency of plant root system phenotyping through digitization and automation

Root system architecture (RSA) determines unevenly distributed water and nutrient availability in soil. Genetic improvement of RSA, therefore, is related to crop production. However, RSA phenotyping has been carried out less frequently than above-ground phenotyping because measuring roots in the soil is difficult and labor intensive. Recent advancements have led to the digitalization of plant measurements; this digital phenotyping has been widely used for measurements of both above-ground and RSA traits. Digital phenotyping for RSA is slower and more difficult than for above-ground traits because the roots are hidden underground. In this review, we summarized recent trends in digital phenotyping for RSA traits. We classified the sample types into three categories: soil block containing roots, section of soil block, and root sample. Examples of the use of digital phenotyping are presented for each category. We also discussed room for improvement in digital phenotyping in each category.     

Distributed Generation of Shared RSA Keys in Mobile Ad Hoc Networks

Mobile Ad hoc NETworks(MANET) is a totally new concept in which mobile nodes are able to communicate together over wireless links in an independent manner,without needing any fixed physical infrastructure and centralized organizational/administrative infrastructure.However,the nature of ad hoc networks makes them very vulnerable to security threats.Generation and distribution of shared keys for CA(Certification Authority)is challenging in security solution based on distributed PKI/CA.Those solutions that have been proposed in the literature and some issues are discussed.This paper propose the solution of distributed generation of shared CA keys based on threshold RSA cryptosystems,with which the security and robustness of system is enhanced.     

Chaotic clone optimization algorithm based on equivalent division strategy

The way of clonal selection algorithm randomly generated population that will easily lead to numbers of non uniform distribution of values in the solution space, thus increasing the data redundancy phenomenon.To overcome the shortcomings of clonal selection algorithm, a chaotic clonal optimization algorithm for function optimizing is proposed by combining clonal selection algorithm, chaos optimization. This algorithm uses chaotic characteristics randomness, ergodicity and regularity to avoid trapping around local optimal. Equivalent division strategy is introduced by reducing the possible data redundancy phenomenon. The simulation results show that the proposed algorithm can converge to the global optimum at quicker rate in a given range.     

A novel shuffled frog leaping algorithm for ICPT power programming

A new mode of inductively coupled power transfer (ICPT) is presented to city electrization traffic vehicle power supply optimization. The power supply distribution plan and ICPT technology are investigated. To avoid the local optimal of shuffled frog leaping algorithm (SFLA),a novel algorithm based on mutative scale chaos search and SFLA is presented. It is applied to inductively coupled power transfer substation optimal planning. The advantages of global and local search strategies for SFLA are combined with the proposed algorithm. In order to implement local refined search to improve local chaotic search ability and to enhance the solution accuracy, mutative scale chaos search is introduced to the proposed algorithm. The minimum annual expense of the proposed algorithm is 2.39% less than that of SFLA, which shows its advantage.     

Including root architecture in a crop model improves predictions of spring wheat grain yield and above‐ground biomass under water limitations

Although the root length density (RLD) of crops depends on their root system architecture (RSA), the root growth modules of many 1D field crop models often ignored the RSA in the simulation of the RLD. In this study, two model set‐up scenarios were used to simulate the RLD, above‐ground biomass (AGB) and grain yield (GY) of water‐stressed spring wheat in Germany, aiming to investigate the impact of improved RLD on AGB and GY predictions. In scenario 1, SlimRoot, a root growth sub‐model that does not consider the RSA of the crop, was coupled to a Lintul5‐SlimNitrogen‐SoilCN‐Hillflow1D crop model combination. In scenario 2, SlimRoot was replaced with the Somma sub‐model which considered the RSA for simulating RLD. The simulated RLD, AGB and GY were compared with observations. Scenario 2 predicted the RLD, AGB and GY with an average root mean square error (RMSE) of 0.43 cm/cm³, 0.59 t/ha and 1.03 t/ha, respectively, against 1.03 cm/cm³, 1.20 t/ha and 2.64 t/ha for scenario 1. The lower RMSE under scenario 2 shows that, even under water‐stress conditions, predictions of GY and AGB can be improved by considering the RSA of the crop for simulating the RLD.     

Research on Cooperative Design Network Security Based on IP-VPN

As the important method and instrument of agile manufacture,the technology of distributed collaborative design and manufacturing has become the hotspot of manufacturing. The basic concept and key technologies of IP_VPN are introduced in this paper,and a collaborative design network model based on IP_VPN is presented. Distributed collaborative design is a multi_user,multitask involved system, which is consisted of lots of collaborative processs,so the network security is the key of distributed collaborative design. We research on the security of collaborative design network based on IP_VPN, hence get a conclusion:we can construct an economical?practical and secure collaborative design network system by the application of data encryption,user authentication and access control based on the role,etc.     

Root phenotyping: important and minimum information required for root modeling in crop plants

As plants cannot relocate, they require effective root systems for water and nutrient uptake. Root development plasticity enables plants to adapt to different environmental conditions. Research on improvements in crop root systems is limited in comparison with that in shoots as the former are difficult to image. Breeding more effective root systems is proposed as the “second green revolution”. There are several recent publications on root system architecture (RSA), but the methods used to analyze the RSA have not been standardized. Here, we introduce traditional and current root-imaging methods and discuss root structure phenotyping. Some important root structures have not been standardized as roots are easily affected by rhizosphere conditions and exhibit greater plasticity than shoots; moreover, root morphology significantly varies even in the same genotype. For these reasons, it is difficult to define the ideal root systems for breeding. In this review, we introduce several types of software to analyze roots and identify important root parameters by modeling to simplify the root system characterization. These parameters can be extracted from photographs captured in the field. This modeling approach is applicable to various legacy root data stored in old or unpublished formats. Standardization of RSA data could help estimate root ideotypes.