scholarly journals Chaos-Based Synchronized Dynamic Keys and Their Application to Image Encryption with an Improved AES Algorithm

2021 ◽  
Vol 11 (3) ◽  
pp. 1329
Author(s):  
Chih-Hsueh Lin ◽  
Guo-Hsin Hu ◽  
Che-Yu Chan ◽  
Jun-Juh Yan

This study aimed to design chaos-based synchronized dynamic keys and develop an improved chaos-based advanced encryption standard (AES) algorithm with the proposed synchronized random keys. First, based on sliding mode control (SMC) technology, a rippling control scheme was introduced to guarantee the synchronization between master–slave discrete chaotic systems. Under the synchronization, the same dynamic random chaos signals could be simultaneously obtained at the transmitter and receiver in communication systems. Then, a novel modified AES cryptosystem with dynamic random keys based on chaos synchronization was presented. In a traditional AES cryptosystem, a static key is used, and it must be exchanged in advance and confirmed to be safely kept. However, in the proposed design, by introducing the synchronization technology of chaotic systems, the static key becomes dynamic and random, and it does not need to be kept or transmitted in open channels. Consequently, the disadvantage of key storage could be eliminated and the security of encryption could be improved. Finally, the developed chaos-based AES (CAES) algorithm has been applied to construct a novel image encryption algorithm. The statistical analysis, histogram, information entropy, and correlation indexes have been calculated and analyzed through simulation experiments in order to demonstrate the capability and improvement of this presented CAES cryptosystem.

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Jiming Zheng ◽  
Zheng Luo ◽  
Zhirui Tang

In this paper, an improved two-dimensional logistic-sine coupling map (N2D-LSCM) and an improved Henon map (NHenon) are proposed. Furthermore, by combining N2D-LSCM and NHenon map, an image encryption algorithm is proposed based on these two chaotic systems and DNA coding. The chaotic sequences generated by N2D-LSCM are used as the parameters of NHenon. In the scrambling stage, DNA encoding is carried out for pixels after scrambling by two chaotic sequences generated by N2D-LSCM; in the stage of diffusion, DNA random coding acts on random matrix obtained by two chaotic sequences generated by NHenon, and DNA XOR operation is carried out with the image obtained in the scrambling stage to diffuse. Compared with other 2D map for image encryption algorithm, this algorithm exhibits good security and holds high efficiency.


2019 ◽  
Vol 9 (4) ◽  
pp. 781 ◽  
Author(s):  
Xiong Wang ◽  
Ünal Çavuşoğlu ◽  
Sezgin Kacar ◽  
Akif Akgul ◽  
Viet-Thanh Pham ◽  
...  

Chaotic systems without equilibrium are of interest because they are the systems with hidden attractors. A nonequilibrium system with chaos is introduced in this work. Chaotic behavior of the system is verified by phase portraits, Lyapunov exponents, and entropy. We have implemented a real electronic circuit of the system and reported experimental results. By using this new chaotic system, we have constructed S-boxes which are applied to propose a novel image encryption algorithm. In the designed encryption algorithm, three S-boxes with strong cryptographic properties are used for the sub-byte operation. Particularly, the S-box for the sub-byte process is selected randomly. In addition, performance analyses of S-boxes and security analyses of the encryption processes have been presented.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Hua Chen ◽  
Wen Chen ◽  
Binwu Zhang ◽  
Haitao Cao

A second-order sliding mode (SOSM) controller is proposed to synchronize a class of incommensurate fractional-order chaotic systems with model uncertainties and external disturbances. Based on the chattering free SOSM control scheme, it can be rigorously proved that the dynamics of the synchronization error is globally asymptotically stable by using the Lyapunov stability theorem. Finally, numerical examples are provided to illustrate the effectiveness of the proposed controller design approach.


Author(s):  
V Goutham Bharadwaja ◽  
Yashas M S ◽  
Yathendra Yadav T V ◽  
Gelvesh G

Security is a crucial side to preserve the confidentiality of information such as pictures and text. The probability of an assailant attempting to access the image in the course of transferring process is high as assailant may get hold of important data. Therefore, encryption methods are used for securing the data. A novel image encryption algorithm that is a combination of the AES algorithm and the chaos sequence is proposed in this paper. The project will use AES for encryption and decryption of the image transfer because AES is capable of solving problem that cannot be resolved by different algorithms. The original image is transformed into cipher-image using a share secret key and this process is called encryption while the reverse of encryption process is known as decryption. This method’s sensitivity to the initial values and input image, even the tiniest changes within these values will result in significant changes in the encrypted image. We show that this approach can shield the image against different attacks exploitation using histogram analysis.


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