Jun Peng

A novel scheme for image encryption based on piecewise linear chaotic map

Recently, the chaos based cryptographic algorithms have suggested some meaningful techniques to develop efficient image encryption schemes. In this paper, we propose a new digital image encryption scheme based on the piecewise linear chaotic map (PWLCM) in order to meet the requirements of the secure encryption. The proposed scheme is described in detail, along with the security analyses including key space analysis, sensitivity analysis, information entropy analysis and differential attack analysis. The results show that the suggested image encryption scheme has some properties desirable in a good security cryptosystem.

An Image Encryption Scheme Based on Chaotic Map

In this paper, a novel block digital image encryption scheme based on a chaotic coupled map lattices (CML) is reported. Within this scheme, an original image is decomposed into sub-blocks with a given size, and an external secret key with 192-bit is used and mapped to the system parameters, which are employed to generate a spatiotemporal chaotic binary sequence matrix to encrypt the block original image. Besides, the former sub-block encrypted result will be acted as a feedback to the following sub-block encryption process. The proposed scheme is described in detail, along with the security analyses such as key space analysis, sensitivity analysis, information entropy analysis and correlation coefficients analysis of adjacent pixels. The computer simulation results indicate that the suggested image encryption scheme has some properties desirable in a good security cryptosystem.

A Novel Digital Image Encryption Algorithm Based on Hyperchaos by Controlling Lorenz System

This paper presents a new image encryption algorithm based on a four-dimensional (4D) continuous-time autonomous hyperchaotic Lorenz system by introducing a simple state feedback controller. The proposed algorithm is described in detail, along with the security analyses including sensitivity analysis, information entropy analysis and differential attack analysis. The results show that the suggested algorithm has some properties desirable in a good security cryptosystem.

A Block Cipher Based on a Hybrid of Chaotic System and Feistel Network

Based on the hybrid of piecewise linear chaotic map (PWLCM) and Feistel network, a block cipher algorithm with a 128-bit length key is proposed. Within the algorithm, an 8x8 S-Box generated by chaotic map is used to realize the round function F, and PWLCM is employed to determine the input of the S-Boxes. The algorithm operates on 32-bit plaintext blocks through 16 rounds computing. The experiment results and differential and linear cryptanalysis indicate that the proposed cipher has excellent diffusion and confusion properties, and it is very sensitive to the keys and the plaintexts. The inherent properties of chaos will greatly increase the complicated and unpredictability of the ciphertexts. Some future works are also considered in this paper.

Design and Analysis of an Image Encryption Scheme Based on Chaotic Maps

This paper proposes an image encryption scheme based on a new 3D polynomial differential system which is derived from the Lorenz system. The binary sequences generated from the chaotic system are used to construct the desired cipher stream so as to encrypt the original image. The proposed scheme is described in detail, along with experimental example and security analyses including key space analysis, analysis of correlation of adjacent pixels, differential attack analysis and information entropy analysis. The results show that the suggested scheme has some excellent properties and can be used to construct cryptosystem with high practical security to meet the requirements of Internet on security.

A Novel Hash Function Based on Hyperchaotic Lorenz System

This paper presented a novel iterated hash function based on a four-dimensional (4D) hyperchaotic Lorenz system by introducing a simple state feedback controller. Besides, a double-pipe structure was employed to design hash function in order to obtain the better cryptographic properties. This function encodes a message of arbitrary length into a hash value with a fixed 128-bit length. Theoretical analysis and computer simulation indicate that the proposed hash function possesses the advantages of irreversibility, weak collision and flexibility. Some of performance analysis such as one-way property analysis and attacks resistance analysis are conducted and the results show that the proposed has function hash desirable security properties.

Research on Reform and Practice in Bilingual Teaching for Curriculum of Data Structure and Algorithm

A significant research on reform and practice in bilingual teaching for the course of Data Structure and Algorithm is presented in this paper. The specific course teaching model suitable for practical situation of the university that the researchers are working for is gradually built up through integrating international concepts of higher education, constructing comprehensive teaching resources, reforming teaching methods and strategies, and training a high-level bilingual teaching team. It is proved by the practice that the teaching quality and comprehensive ability of undergraduates are being improved, the capability of teaching staff is being promoted, and the demonstration and radiation effects of the course are emerging gradually. All of these improvements indicate that the reform on the course is effective as the goal of course planning is successfully achieved.

Method and research on Chinese predicate recognition based on feature

This paper puts forward n method of Chinese predicate recognition based on the features study. And according to the sentences predicate center coming out of features, we obtain the characteristic knowledge of the predicate based on the language bank of artificial welled marks, and make use of characteristic knowledge to identify predicate. Finally, In the open test the accuracy rate of Chinese predicate recognition closes to 84%, and in the closed test the accuracy rate of Chinese predicate recognition closes to 86%.

The study of code density histogram testing method to high-speed ADC based on DSP

Code density histogram testing method based on digital signal processor is one of dynamic testing methods of high-speed analog-to digital converters. It can evaluate the performance of high speed ADC accurately and quickly. The theory of Code density histogram testing method is analyzed. A suit of high-speed ADC dynamic testing station based on PC. DSP. and FIFO was built that can be operated easily. Its hardware design and software program were fulfilled and realized dynamic testing using code density histogram testing method to high-speed ADCM80 (S bits). Testing result indicates the dynamic testing station is feasible and operated easily.

Spatiotemporal chaos-based secure image transmission scheme by using spread-spectrum over the internet

Based on one-way coupled map lattices model (OCML), binary spatiotemporal chaotic sequences are generated and employed in the application of image spread-spectrum communication over the Internet. Since the spatiotemporal chaotic sequences are very sensitive to the coupled coefficient, initial value of driven sequence and as well as control parameters, the difficulties of cracking chaotic spread-spectrum sequences are increased greatly. Furthermore, the system secure keys are encrypted by using RSA algorithm so as to guarantee the consistency of parameters that used by image sender and receiver, as a result the security and reliability of the scheme are enhanced. The results of numerical stimulation indicate the scheme proposed in this paper is feasible, and some cryptography properties of this system are considered in terms of key space and the sensitivity of encrypted image with respect to the key.