scholarly journals A new image encryption algorithm based on the OF-LSTMS and chaotic sequences

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yi He ◽  
Ying-Qian Zhang ◽  
Xin He ◽  
Xing-Yuan Wang

AbstractIn this paper, a novel image encryption algorithm based on the Once Forward Long Short Term Memory Structure (OF-LSTMS) and the Two-Dimensional Coupled Map Lattice (2DCML) fractional-order chaotic system is proposed. The original image is divided into several image blocks, each of which is input into the OF-LSTMS as a pixel sub-sequence. According to the chaotic sequences generated by the 2DCML fractional-order chaotic system, the parameters of the input gate, output gate and memory unit of the OF-LSTMS are initialized, and the pixel positions are changed at the same time of changing the pixel values, achieving the synchronization of permutation and diffusion operations, which greatly improves the efficiency of image encryption and reduces the time consumption. In addition the 2DCML fractional-order chaotic system has better chaotic ergodicity and the values of chaotic sequences are larger than the traditional chaotic system. Therefore, it is very suitable to image encryption. Many simulation results show that the proposed scheme has higher security and efficiency comparing with previous schemes.

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yingchun Hu ◽  
Simin Yu ◽  
Zeqing Zhang

In this paper, the security analysis of a color image encryption algorithm based on Hopfield chaotic neural network is given. The original chaotic image encryption algorithm includes permutation encryption and diffusion encryption. The result of cryptanalysis shows that the chaotic sequences generated by this algorithm are independent of plaintext image, and there exist equivalent permutation key and equivalent diffusion key. Therefore, according to chosen-plaintext attack, the equivalent diffusion key and the equivalent permutation key can be obtained by choosing two special plaintext images and the corresponding ciphertext images, respectively, and the plaintext image is further recovered from the ciphertext image. Theoretical analysis and numerical simulation experiment results verify the effectiveness of the analytical method. Finally, some improved suggestions for the original encryption algorithm are proposed to promote the security.


2014 ◽  
Vol 556-562 ◽  
pp. 5168-5171 ◽  
Author(s):  
Yan Xu

The author proposes a novel DCT domain image encryption algorithm based on Lorenz chaotic system. The paper firstly subdivides digital image into sub-images, each of which is transformed with DCT transform. Then some DCT transform coefficients are selected with filtering. Finally the retained DCT transform coefficients are cross encrypted with three chaotic sequences which Lorenz chaotic system generates. Simulation experiments and secure performance analysis show that the algorithm has a good encryption effect and anti-attack abilities.


2020 ◽  
Vol 30 (15) ◽  
pp. 2050233
Author(s):  
Guodong Ye ◽  
Kaixin Jiao ◽  
Huishan Wu ◽  
Chen Pan ◽  
Xiaoling Huang

Herein, an asymmetric image encryption algorithm based on RSA cryptosystem and a fractional-order chaotic system is proposed. Its security depends on RSA algorithm. First, a pair of public and private keys is generated by RSA algorithm. Subsequently, a random message shown as plaintext key information is encrypted by the public key and RSA to achieve ciphertext key information. Next, a new transformation map is established to generate the initial key according to the ciphertext key information. Subsequently, the initial key is substituted into a fractional hyperchaotic system equation to calculate the keystream. Finally, permutation and diffusion operations are employed to encrypt a plain image to obtain the final cipher image. In the proposed algorithm, different keys for encryption and decryption are designed under an asymmetric architecture. The RSA algorithm and fractional chaotic system are combined to encrypt images; in particular, a fast algorithm for computing power multiplication is employed, which significantly improves the encryption effect and enhances the security. Simulation results show that the proposed algorithm is effective and applicable to image protection.


Author(s):  
Zhang Zehui ◽  
Yao Fu ◽  
Tiegang Gao

Image encryption algorithms usually have two processes: permutation and diffusion. In order to enhance the performance of the permutation process, this study proposes a dynamic permutation method based on XOR operation and sorting. Combined with the hyper-chaotic system, SHA-256, the proposed permutation method and the simplified advanced encryption system (S-AES), a novel image encryption algorithm is presented in this paper. Firstly, the SHA-256 is used to generate initial condition values of the chaotic system and control parameters of the permutation method. Then, the chaotic system generates pseudo-random numbers, which are used in the permutation method and S-AES. Finally, the proposed permutation method and S-AES are used to encrypt the plain-image. In particular, parallel computing is used in this study to accelerate encryption speed. The results and analysis indicate that the proposed algorithm has excellent security to resist various typical attacks and fast encryption speed.


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