Biblio

In our daily lives, the advances of new technology can be used to sustain the development of people across the globe. Particularly, e-government can be the dynamo of the development for the people. The development of technology and the rapid growth in the use of internet creates a big challenge in the administration in both the public and the private sector. E-government is a vital accomplishment, whereas the security is the main downside which occurs in each e-government process. E-government has to be secure as technology grows and the users have to follow the procedures to make their own transactions safe. This paper tackles the challenges and obstacles to enhance the security of information in e-government. Hence to achieve security data hiding techniques are found to be trustworthy. Reversible data hiding (RDH) is an emerging technique which helps in retaining the quality of the cover image. Hence it is preferred over the traditional data hiding techniques. Modification in the existing algorithm is performed for image encryption scheme and data hiding scheme in order to improve the results. To achieve this secret data is split into 20 parts and data concealing is performed on each part. The data hiding procedure includes embedding of data into least significant nibble of the cover image. The bits are further equally distributed in the cover image to obtain the key security parameters. Hence the obtained results validate that the proposed scheme is better than the existing schemes.

In this paper, an image encryption scheme based on dynamic DNA sequence and two dimension logistic map is proposed. Firstly two different pseudo random sequences are generated using two dimension Sine-Henon alteration map. These sequences are used for altering the positions of each pixel of plain image row wise and column wise respectively. Secondly each pixels of distorted image and values of random sequences are converted into a DNA sequence dynamically using one dimension logistic map. Reversible DNA operations are applied between DNA converted pixel and random values. At last after decoding the results of DNA operations cipher image is obtained. Different theoretical analyses and experimental results proved the effectiveness of this algorithm. Large key space proved that it is possible to protect different types of attacks using our proposed encryption scheme.

In this paper, we introduce a fast, secure and robust scheme for digital image encryption using chaotic system of Lorenz, 4D hyper-chaotic system and the Secure Hash Algorithm SHA-1. The encryption process consists of three layers: sub-vectors confusion and two-diffusion process. In the first layer we divide the plainimage into sub-vectors then, the position of each one is changed using the chaotic index sequence generated with chaotic attractor of Lorenz, while the diffusion layers use hyper-chaotic system to modify the values of pixels using an XOR operation. The results of security analysis such as statistical tests, differential attacks, key space, key sensitivity, entropy information and the running time are illustrated and compared to recent encryption schemes where the highest security level and speed are improved.