scholarly journals A new speech encryption algorithm based on dual shuffling Hénon chaotic map

Author(s):  
Obaida M. Al-hazaimeh

Over the past few decades, many algorithms have been proposed to improve the performance of speech encryption over un-secure channel (i.e., Internet). In this paper, the security level was enhanced using a dynamic dual chaotic based on Hénon chaotic map. In the proposed algorithm, the speech elements are shuffled in a random fashion. Moreover, when both Hénon state variables are free to be used for shuffling the index is toggled randomly between them according to toggle bit. After index shuffling each speech element is modified with XOR operation between the original speech element value and the key that is selected randomly from the updated key table. The same chaotic map is used to initiate the empty or full table and provide new table entries from the values that are already shuffled. The experimental results show that the proposed crypto-system is simple, fast with extra random toggling behavior. The high order of substitution make it sensitive to initial condition, common cryptanalysis attacks such as linear and differential attacks are infeasible.

Author(s):  
Obaida M. Al-hazaimeh

This paper introduces a dynamic speech encryption algorithm based on Lorenz chaotic map over internet protocol to enhance the services of the real-time applications such as increases the security level and reduces latency. The proposed algorithm was divided into two processes: dynamic key generation process using 128-bit hash value to dynamically alter the initial secret keys, and encryption and decryption process using Lorenz system. In the proposed algorithm, the performance evaluation is carried out through efficient simulations and implementations and statistical analysis. In addition, the average time delay in the proposed algorithm and some of the existing algorithms such as AES is compared. The obtained results concluded that, the proposed dynamic speech encryption algorithm is effectually secured against various cryptanalysis attacks and has useful cryptographic properties such as confusion and diffusion for better voice communication in the voice applications field in the Internet.


In this work, speech encryption using synchronized fixed-point chaotic map-based stream ciphers (SFPCM-SC) is suggested. Five chaotic maps named quadratic, henon, logistic, lozi and duffing are synchronized by using master-slave synchronization technique and then used to generate the pseudo random bit generator (PRBG) using fixed-point converter. The PRBG is then Xor-ed with digitized speech signal where the encrypted signal is created. In the other side, the same map is synchronized with the master one and used to recover the original speech signal. First this work is simulated by using MATLAB and then built the design using Xilinx system generator (XSG). Finally, the hardware co-simulation is applied for the proposed system by using FPGA SP605 XC6SLX45T device. The results show that the error between master and slave become zero after a small period and the original speech signal is recovered with real time environment in successful.


Author(s):  
Fawad Masood ◽  
Maha Driss ◽  
Wadii Boulila ◽  
Jawad Ahmad ◽  
Sadaqat Ur Rehman ◽  
...  

AbstractMedical images possess significant importance in diagnostics when it comes to healthcare systems. These images contain confidential and sensitive information such as patients’ X-rays, ultrasounds, computed tomography scans, brain images, and magnetic resonance imaging. However, the low security of communication channels and the loopholes in storage systems of hospitals or medical centres put these images at risk of being accessed by unauthorized users who illegally exploit them for non-diagnostic purposes. In addition to improving the security of communication channels and storage systems, image encryption is a popular strategy adopted to ensure the safety of medical images against unauthorized access. In this work, we propose a lightweight cryptosystem based on Henon chaotic map, Brownian motion, and Chen’s chaotic system to encrypt medical images with elevated security. The efficiency of the proposed system is proved in terms of histogram analysis, adjacent pixels correlation analysis, contrast analysis, homogeneity analysis, energy analysis, NIST analysis, mean square error, information entropy, number of pixels changing rate, unified average changing intensity, peak to signal noise ratio and time complexity. The experimental results show that the proposed cryptosystem is a lightweight approach that can achieve the desired security level for encrypting confidential image-based patients’ information.


2018 ◽  
Vol 229 ◽  
pp. 04007
Author(s):  
Eko Pradjoko ◽  
Lukita Wardani ◽  
Hartana ◽  
Heri Sulistiyono ◽  
Syamsidik

The past earthquake records in North Lombok show the high level of earthquake hazard in this area. The maximum magnitude of the earthquake was 6.4 Mw on May 30th, 1979. But, there were no tsunami events records due to those earthquakes. Nevertheless, this area is very close to Mataram City (province capital city) and tourism area. Therefore, the assessment of tsunami hazard is very important. The tsunami simulation was conducted by using COMCOT Model, which is based on the North Lombok Earthquake as the initial condition. The simulation result shows the prediction of tsunami travel time is about 18 ~ 20 minutes from the source location to Mataram City. The height of the tsunami wave is 0.13 ~ 0.20 meters due to the earthquake magnitude is about 6 Mw.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Zhenjun Tang ◽  
Ye Yang ◽  
Shijie Xu ◽  
Chunqiang Yu ◽  
Xianquan Zhang

Image encryption is a useful technique of image content protection. In this paper, we propose a novel image encryption algorithm by jointly exploiting random overlapping block partition, double spiral scans, Henon chaotic map, and Lü chaotic map. Specifically, the input image is first divided into overlapping blocks and pixels of every block are scrambled via double spiral scans. During spiral scans, the start-point is randomly selected under the control of Henon chaotic map. Next, image content based secret keys are generated and used to control the Lü chaotic map for calculating a secret matrix with the same size of input image. Finally, the encrypted image is obtained by calculating XOR operation between the corresponding elements of the scrambled image and the secret matrix. Experimental result shows that the proposed algorithm has good encrypted results and outperforms some popular encryption algorithms.


Author(s):  
Kshiramani Naik ◽  
Arup Kumar Pal

In this paper, an image encryption scheme based on reversible integer wavelet transform (IWT) with chaotic logistic map is designed. The proposed cryptosystem is applicable to encipher both the medical and natural images in lossless and lossy manners, respectively. Initially, the original image is transformed with the multilevel of IWT, then the image data set is divided into low sub-band (approximation part) and high sub-bands (detail part). The approximation part gets confused with the chaotic logistic map followed by the bit plane decomposition. Next, the individual bit planes are further diffused with several binary key metrics, generated using a chaotic logistic map. The proposed key schedule derives several large size of binary key metrics from a small size of key. Based on the type of applications, the detail part is considered for lossless/lossy compression. The lossless/lossy compressed detail part is further considered only for confusion process using the logistic map for the sake of enhancing the security level. Finally, the cipher image obtained after inverse IWT is significantly dissimilar than original image. The scheme has been tested on several standard medical and natural images and the experimental results substantiate that a small size of key is enough to protect the content of images completely. The security analysis reveals that the proposed scheme is suitable for protecting the image data effectively.


2018 ◽  
Vol 29 (07) ◽  
pp. 1850058 ◽  
Author(s):  
Nabil Ben Slimane ◽  
Nahed Aouf ◽  
Kais Bouallegue ◽  
Mohsen Machhout

In this paper, an efficient scheme for image encryption based on the nested chaotic map and deoxyribonucleic acid (DNA) is introduced. In order to generate the initial condition values of the nested chaotic system, the Secure Hash Algorithm SHA-256 is used. The algorithm consists of two main layers: confusion and diffusion. In the first layer, the nested chaotic map is employed to create the scrambled image. The scrambled image is obtained through the ascending sorting of the first component of the nested chaotic index sequence. To ensure higher sensitivity, higher complexity and higher security, DNA sequence and DNA operator are employed additionally with the nested chaotic map and hash algorithm to modify the pixel values. The important advantages of our algorithm are the improvement of Number of Pixel Change Rate (NPCR), Unified Average Changing Intensity (UACI) and entropy, which improve resistivity against several attacks. Experimental results and relevant security analysis demonstrated that our proposed encryption scheme has the highest security level because it is more complicated, and it has a sufficiently large key space. The proposed method is compared to other recent image encryption schemes using different security analysis factors, including NPCR, UACI, correlation coefficients (CCs), encryption quality (EQ) and entropy. It is also resistant to noise (Salt and Pepper, Gaussian and speckle) and data loss attacks. The illustrated results demonstrated that the proposed image encryption scheme is efficient, and can be adopted for image encryption and transmission.


2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Hui Ren ◽  
Jun Wang ◽  
Qiong-Hua Wang

We introduce an image encryption method based on computer-generated hologram (CGH) and two-dimensional Sine Logistic modulation map (2D-SLMM). We combine CGH and 2D-SLMM to improve encryption security. During the encryption process, the hologram needs to be logistically modulated by 2D-SLMM. This logistic modulation technique can avoid complex algorithms. Simulation results and security analysis demonstrate that the proposed approach has a high security level, good invisibility of image information in ciphertext, large key space, and strong robustness.


Author(s):  
Haeyoung Kim ◽  
Hitoshi Yamada ◽  
Hiroshi Katsuchi ◽  
Soichiro Nakamura

Abnormally high temperature inside the long, undergrounded tunnel is a problem in the urban area. As one of the countermeasures, a ventilation fan has been operated. However, the insufficient temperature reduction effect and high cost are an issue and improvement is required. In this study, in order to improve the operating plan of ventilation, the flow field and temperature distribution characteristics are clarified by computational thermal fluid analysis, and the operation of the optimum ventilation was decided. The dominant factors for the temperature rising were identified as traffic volume, lane axis wind speed, cross flow ventilation, and heat flux between tunnel body and air in tunnel. In the analysis, we focused on these four factors, and applied these factors obtained from long-term on-site measurement to the boundary condition and the initial condition. In addition, the amount of heat from vehicle traffic was calculated based on the measurement and the past report results. The analytical model is 1000 m partial tunnel section where the temperature rising was intense. The validation of numerical model was verified from the comparison between the analysis results and the measured values. It was confirmed that the effect of increasing lane axis wind speed as a countermeasure was not significant, and the ventilation amount of crosswind is recommended as 60 m3/s.


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