No abstract

No abstract

No abstract

Chaotic maps used to shuffle and manipulate the image pixels are important for image encryption (IE). In this study, a novel 2D optimized chaotic map (OPMAP) using a triple-objective differential evolution (TODE) algorithm is presented for IE. A model for OPMAP with eight decision variables is empirically designed, and then its variables are determined utilizing TODE through minimizing a triple-objective function that involving Lyapunov exponent (LE), entropy and 0-1 test. OPMAP is assessed with respect to credible measurements like bifurcation, 3D phase space, LE, 0-1 test, permutation entropy (PE) and sample entropy (SE). The capability of OPMAP is then verified through an IE scheme including permutation and diffusion through various cryptanalyses: key space 2 298 , mean entropy 7.9995, mean correlation 13.61E-5, number of pixels changing rate (NPCR) 99.6093, unified average changing intensity (UACI) 33.4630 and encryption processing time (EPT) 0.2919 (s). A detailed review of IE schemes reported elsewhere is presented and IE performance of OPMAP is also validated by comparison with those IE schemes with and without optimization used. The 2D-OPMAP-based IE is faster and has low computational complexity. Moreover, the proposed it shows better cryptanalysis results for the most of the comparisons.

This study focuses on the gain of using progressive download instead of legacy download for streamable media files for wireless multicasting networks. With progressive download, the media content can be played after some waiting time, while the downloading still continues in the background. We focus on 3GPP's wireless multimedia broadcast multicast system (MBMS). First we provide a legacy MBMS download system optimized for waiting time to play the media. Then we provide a progressive MBMS download system to compare the gain in waiting time. Reliability is assumed to be provided with a FEC mechanism. We considered Reed Solomon and Raptor FEC and finally provided comparisons of both FEC methods with regards to savings in waiting time for progressive download. The results encourage the usage of progressive download instead of legacy download mechanism where the data file is streamable, for improved user experience for 3G wireless multicasting systems.