Proposed Image Encryption Research Articles

Design of digital image encryption based on elliptic curve cryptography (ECC) algorithm and Radix-64 conversion

The billions of bits of information are transferred each second through the internet every day. The information may be text, image, audio or video etc, accordingly, we need some protection mechanism while sharing confidential data. Generally, RSA algorithm is used for encrypting the Secret images. However, the security provided by Elliptic Curve Cryptography (ECC) is higher with lower sized key than the RSA algorithm. So, this article proposes an extended Elliptic Curve encryption approach for encrypting the secret images. In this system, the secret image is partitioned into three color image planes such as Red, Green and Blue. By applying Radix-64 encoding and Mapping table, these planes are converted into elliptic curve points and then these points are encrypted using ECC algorithm. Again, these points are applied to the Radix-64 decoding and the mapping table to get ciphered-image. At last, the key parameters such as a, b, p and Generator point (G) are embedded in the last four pixel positions of the ciphered-image. In order to get the original secret image, the recipient must extract these key parameters from the encrypted image and then apply the remaining processes to the encrypted image in the opposite order. Experimental results tested using MATLAB R2021b and it shows that the NPCR and UACI values are 99.54% and 28.73 % and better quality feature is attained since the entropy value is almost closer to eight. So, the proposed image encryption has robust capacity to fight against the differential attack.

A Format-compatible Searchable Encryption Scheme for JPEG Images Using Bag-of-words

The development of cloud computing attracts enterprises and individuals to outsource their data, such as images, to the cloud server. However, direct outsourcing causes the extensive concern of privacy leakage, as images often contain rich sensitive information. A straightforward way to protect privacy is to encrypt the images using the standard cryptographic tools before outsourcing. However, in such a way the possible usage of the outsourced images would be strongly limited together with the services provided to users, like the Content-Based Image Retrieval (CBIR). In this article, we propose a secure outsourced CBIR scheme, in which an encryption scheme is designed for the widely used JPEG-format images, and the secure features can be directly extracted from such encrypted images. Specifically, the JPEG images are encrypted by the block permutation, intra-block permutation, polyalphabetic cipher, and stream cipher. Then secure local histograms are extracted from the encrypted DCT blocks and the Bag-Of-Words (BOW) model is further used to organize the encrypted local features to represent the image. The proposed image encryption gets all of the image data protected and the experimental results show that the proposed scheme achieves improved accuracy with a small file size expansion.

Synchronization of chaotic-type delayed neural networks and its application

Our proposed image encryption is based on synchronization of chaotic fuzzy cellular neural networks (FCNNs) with different time delays and uses sampled-data controller. (i) It is known that the chaotic system plays a vital role in secure communication. (ii) FCNNs are more suitable for image processing due to its local connectedness. (iii) There are some results derived on theory part for the problem of synchronization of chaotic delayed FCNNs. (iv) We raise the following question: Is it possible to utilize these obtained chaotic values via FCNNs to image encryption? (v) Finally, we tried the above and succeed. Moreover, numerical instance and comparison results show that the proposed scheme works well and is resistant to differential attack.

Image Encryption with Variable Length Key

ABSTRACTWe propose a new image encryption algorithm with variable length running key based on a modified tent map. This modified tent map can generate uniform distribution pseudo-random number sequence. In the proposed image encryption, we employ the strategy of variable length running key which enlarges key value space, the strategy of one-time running key which is resilient to known/chosen plaintext attack, the strategy of cipher disturbance which minimizes dynamical degradation of digital chaos. Simulations have been carried out and the results demonstrate the strong survival ability of our scheme.

A new image encryption algorithm based on non-adjacent coupled map lattices

We propose a new image encryption algorithm which is based on the spatiotemporal non-adjacent coupled map lattices. The system of non-adjacent coupled map lattices has more outstanding cryptography features in dynamics than the logistic map or coupled map lattices does. In the proposed image encryption, we employ a bit-level pixel permutation strategy which enables bit planes of pixels permute mutually without any extra storage space. Simulations have been carried out and the results demonstrate the superior security and high efficiency of the proposed algorithm.

A symmetric image encryption algorithm based on mixed linear–nonlinear coupled map lattice

We propose a new image encryption algorithm based on the spatiotemporal chaos of the mixed linear–nonlinear coupled map lattices. This spatiotemporal chaotic system has more outstanding cryptography features in dynamics than the logistic map or the system of coupled map lattices does. In the proposed image encryption, we employ the strategy of bit-level pixel permutation which enables the lower bit planes and higher bit planes of pixels permute mutually without any extra storage space. Simulations have been carried out and the results demonstrate the superior security and high efficiency of the proposed algorithm.