Karima Amara Korba

The main purpose of this thesis is to generate new chaotic maps to secure the transmission of images in the physical layer of wireless multimedia sensor networks. To overcome the flaws of standard chaotic maps and create more complex chaotic dynamics, we suggest hybridization between two cascading maps.

The discrete chaotic maps used are: the new cubic map that has been developed, the Arnold's cat map and the sine map.

In this thesis, we generate two new chaotic parametric cascaded maps 3D Cubic-Sine map and 2D Cubic-Cat map, the first map was used as a chaotic pseudo-random number generator for image encryption with two techniques; cryptography and steganography the second map was used for quadrature amplitude modulation scrambling (QAM).

Simulations of complexity dynamics were carried out for the new maps proposed as well as a simulation of transmission using OFDM for the encrypted images with an analysis of the PSNR and BER values as evaluation parameters of the transmission’s quality.

The experimental result’s analysis of the security of the encrypted images and their quality obtained after transmission clearly show the effectiveness and the robustness of the methods proposed in this thesis.