scholarly journals A Novel Audio Encryption Algorithm with Permutation-Substitution Architecture

Electronics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 530 ◽  
Author(s):  
Krasimir Kordov
Keyword(s):  
Performance Test ◽  
Noise Analysis ◽  
Random Number Generator ◽  
Encryption Algorithm ◽  
Rate Analysis ◽  
Key Space ◽  
Speed Performance ◽  
Audio Encryption ◽  
Audio Files ◽  
High Level

In this paper, a new cryptographic method is proposed, designed for audio files’ security. The encryption algorithm is based on classic symmetric models using pseudo-random number generator composed with chaotic circle map and modified rotation equations. The scheme of a new pseudo-random generator is presented and used as basis for chaotic bit-level permutations and substitutions applied to audio files structure for successful encryption. The audio encryption and decryption algorithms are described and explained. Proving the high level of security we provide extensive cryptographic analysis including key sensitivity analysis, key-space analysis, waveform and spectrogram analysis, correlation analysis, number of sample change rate analysis, level of noise analysis and speed performance test.

scholarly journals Provide a New Encryption Algorithm for Medical Images and Evaluate the Proposed Algorithm

2019 ◽  
Vol 8 (1) ◽  
pp. 2
Author(s):  
Mehdi Lotfi ◽  
Hossein Kheiri ◽  
Azizeh Jabbari
Keyword(s):  
Differential Equations ◽  
Chaotic Systems ◽  
Medical Information ◽  
Medical Images ◽  
Encryption Algorithm ◽  
Key Generation ◽  
Time Period ◽  
Key Space ◽  
Encryption And Decryption ◽  
Very High

Introduction:  In this paper, an encryption algorithm for the security of medical images is presented, which has extraordinary security. Given that the confidentiality of patient data is one of the priorities of medical informatics, the algorithm can be used to store and send medical image.Material and Methods:  In this paper, the solutions of chaotic differential equations are used to generate encryption keys. This method is more than other methods used in encoding medical images, resistant to statistics attacks, low encryption and decryption time and very high key space. In the proposed algorithm, unlike other methods that use random key generation, this method uses the production of solutions of the chaotic differential equations in a given time period for generating a key. All simulations and coding are done in MATLAB software.Results:   Chaotic Differential Equations have two very important features that make it possible to encode medical images. One is the unpredictability of the system's behavior and the other is a severe sensitivity to the initial condition.Conclusion: These two features make the method resistant to possible attacks to decode the concept of synchronization chaotic systems. Using the results of the method, medical information can be made safer than existing ones.

A Color Image Encryption Algorithm Based on Improved DES

2015 ◽  
Vol 743 ◽  
pp. 379-384 ◽  
Author(s):  
Zhang Li Lan ◽  
Lin Zhu ◽  
Yi Cai Li ◽  
Jun Liu
Keyword(s):  
Random Function ◽  
Color Image ◽  
Logistic Function ◽  
Color Images ◽  
Encryption Algorithm ◽  
Key Generation ◽  
Color Image Encryption ◽  
Generation Algorithm ◽  
Key Space ◽  
Image Encryption Algorithm

Key space will be reduced after using the traditional DES algorithm to directly encrypt color images. Through combining the chaotic capability of the logistic function and by means of a specific algorithm, the fake chaotic son key’s space which is produced by the logistic chaotic pseudo-random function could be acquired. Then use the key generation algorithm to replace the traditional DES key generation algorithm. Experiment illustrates that the proposed algorithm has stronger robustness and anti-jamming capability to noise, and larger key’s space, sensitive initial keys, and better encryption effect, meanwhile it is better immune to multiple attacks.

Image Encryption Algorithm Based on a Novel 4D Chaotic System

2021 ◽  
Vol 15 (4) ◽  
pp. 118-131
Author(s):  
Sadiq A. Mehdi
Keyword(s):  
Chaotic System ◽  
Initial Conditions ◽  
High Sensitivity ◽  
Encryption Algorithm ◽  
Pseudorandom Sequence ◽  
Key Space ◽  
Xor Operation ◽  
Change Intensity ◽  
And Performance ◽  
Image Cryptosystem

In this paper, a novel four-dimensional chaotic system has been created, which has characteristics such as high sensitivity to the initial conditions and parameters. It also has two a positive Lyapunov exponents. This means the system is hyper chaotic. In addition, a new algorithm was suggested based on which they constructed an image cryptosystem. In the permutation stage, the pixel positions are scrambled via a chaotic sequence sorting. In the substitution stage, pixel values are mixed with a pseudorandom sequence generated from the 4D chaotic system using XOR operation. A simulation has been conducted to evaluate the algorithm, using the standardized tests such as information entropy, histogram, number of pixel change rate, unified average change intensity, and key space. Experimental results and performance analyses demonstrate that the proposed encryption algorithm achieves high security and efficiency.

A Novel Algorithm for Block Encryption of Digital Image Based on Chaos

2011 ◽  
Vol 5 (1) ◽  
pp. 59-74 ◽  
Author(s):  
Jun Peng ◽  
Du Zhang ◽  
Xiaofeng Liao
Keyword(s):  
Three Dimensional ◽  
Encryption Algorithm ◽  
Brute Force ◽  
Secret Key ◽  
Image Block ◽  
Differential Attack ◽  
Avalanche Effect ◽  
Chaotic Dynamical System ◽  
Key Space ◽  
Block Encryption

This paper proposes a novel image block encryption algorithm based on three-dimensional Chen chaotic dynamical system. The algorithm works on 32-bit image blocks with a 192-bit secret key. The idea is that the key is employed to drive the Chen’s system to generate a chaotic sequence that is inputted to a specially designed function G, in which we use new 8x8 S-boxes generated by chaotic maps (Tang, 2005). In order to improve the robustness against differental cryptanalysis and produce desirable avalanche effect, the function G is iteratively performed several times and its last outputs serve as the keystreams to encrypt the original image block. The design of the encryption algorithm is described along with security analyses. The results from key space analysis, differential attack analysis, and information entropy analysis, correlation analysis of two adjacent pixels prove that the proposed algorithm can resist cryptanalytic, statistical and brute force attacks, and achieve a higher level of security. The algorithm can be employed to realize the security cryptosystems over the Internet.

scholarly journals Double image multi-encryption algorithm based on fractional chaotic time series

2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Zhenghong Guo ◽  
Jie Yang ◽  
Yang Zhao
Keyword(s):  
Time Series ◽  
Chaotic Time Series ◽  
Encryption Algorithm ◽  
Brute Force ◽  
Double Image ◽  
Key Space ◽  
Plain Image ◽  
Image Pixels ◽  
Brute Force Attack ◽  
The Relationship

AbstractIn this paper, we introduce a new image encryption scheme based on fractional chaotic time series, in which shuffling the positions blocks of plain-image and changing the grey values of image pixels are combined to confuse the relationship between the plain-image and the cipher-image. Also, the experimental results demonstrate that the key space is large enough to resist the brute-force attack and the distribution of grey values of the encrypted image has a random-like behavior.

CIPHER SYSTEMS BASED ON CONTROLLED EXACT CHAOTIC MAPS

2010 ◽  
Vol 20 (12) ◽  
pp. 4039-4053 ◽  
Author(s):  
ALI KANSO
Keyword(s):  
Time Series ◽  
Cycle Length ◽  
Chaotic Maps ◽  
Necessary Conditions ◽  
Logistic Map ◽  
Security Level ◽  
Encryption Scheme ◽  
Key Space ◽  
Suggested Technique ◽  
High Level

In this paper, we present a class of chaotic clock-controlled cipher systems based on two exact chaotic maps, where each map is capable of generating exact chaotic time series of the logistic map. This class is designed in such a way that one map controls the iterations of the second map. The suggested technique results in generating orbits possessing long cycle length and high level of security from the two periodic exact maps. In the first part of this paper, two keystream generators based on two exact chaotic logistic maps are suggested for use in cryptographic applications. The necessary conditions to generate orbits with guaranteed long enough cycle length are established. Furthermore, the generated keystreams are demonstrated to possess excellent randomness properties. In the second part, we suggest a clock-controlled encryption scheme related to Baptista's scheme and based on two exact chaotic logistic maps. This technique results in increasing the size of the key space, and hence may increase the security level against some existing cryptanalytic attacks. Furthermore, it leads to reducing the size of the ciphertext file and propably increasing the encryption speed.

A Novel Color Image Encryption Algorithm Based on Hyperchaotic System and Permutation-Diffusion Architecture

2019 ◽  
Vol 29 (09) ◽  
pp. 1950115 ◽  
Author(s):  
Guangfeng Cheng ◽  
Chunhua Wang ◽  
Hua Chen
Keyword(s):  
Image Encryption ◽  
Color Image ◽  
Encryption Algorithm ◽  
Hyperchaotic System ◽  
Color Image Encryption ◽  
Key Space ◽  
Encryption Algorithms ◽  
Block Permutation ◽  
Encrypted Images ◽  
Differential Attacks

In recent years, scholars studied and proposed some secure color image encryption algorithms. However, the majority of the published algorithms encrypted red, green and blue (called [Formula: see text], [Formula: see text], [Formula: see text] for short) components independently. In the paper, we propose a color image encryption scheme based on hyperchaotic system and permutation-diffusion architecture. The encryption algorithm utilizes a block permutation which is realized by mixing [Formula: see text], [Formula: see text], [Formula: see text] components to strengthen the dependence of each component. Besides, it can reduce time consumption. Then, the key streams generated by the hyperchaotic system are exploited to diffuse the pixels, the three components affect each other again. And in the diffusion process, we can get two totally different encrypted images even though we change the last pixel because the [Formula: see text] component is diffused in reverse order. The experimental results reveal that our algorithm possesses better abilities of resisting statistical attacks and differential attacks, larger key space, closer information entropy to 8, and faster encryption speed compared with other chaos-based color image encryption algorithms.

scholarly journals Influence of Heat Reflective Coating on the Cooling and Pavement Performance of Large Void Asphalt Pavement

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1065
Author(s):  
Nanxiang Zheng ◽  
Junan Lei ◽  
Shoubin Wang ◽  
Zhifeng Li ◽  
Xiaobao Chen
Keyword(s):  
Titanium Dioxide ◽  
Water Permeability ◽  
Performance Test ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Cooling Effect ◽  
Large Void ◽  
Reflective Coating ◽  
Water Permeability Coefficient ◽  
High Level

To reduce the temperature of asphalt pavement in summer, and alleviate the urban heat island effect, a comprehensive method of combining a heat reflective coating and large void asphalt pavement was proposed. Using the developed coating cooling test equipment, the cooling effect of the coating on a large void asphalt mixture was studied in six different proportions, four different colors, and four different dosages, and the durability of the coating was verified by abrasion tests. Finally, the best dosage of the coating was recommended through an adhesion test of the coating, and a water permeability and anti-skid performance test of the pavement. The results show that the reflectivity of the coating can be improved by adding functional fillers, of titanium dioxide and floating beads, into the coating. The order by reflectivity and cooling effect of the four color coatings was green > red > gray > blue, and the maximum cooling value of the green coating reached 9.7 ℃. The cooling performance of the coating decreased with the increase of wear time, and the rate of decrease was fast, then slow, and finally tended to be stable after 20,000 times wear. The coating reduced the anti-skid performance and the water permeability coefficient of large void asphalt pavement, but still maintained a high level. The green coating with 15% titanium dioxide and 10% floating beads is recommended as the cooling coating for large void asphalt pavement, and its dosage should be controlled at about 0.4–0.8 kg/m2.

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