Reciprocal Time Domain Disruption of Image for Secured Communication

摘要

Now a day, the transmission of digital files over the insecure medium such as the internet has been increasing tremendously. The cyber criminals can hack the informative data which are being transmitted through the open network. In such a scenario, security became a crucial factor in safeguarding the information in all sectors such as business, government etc. In this paper, a novel digital image encryption is proposed based on the key generated from chaos-based Lorentz attractor. At first, a confusion and diffusion operation is done in the low-frequency band of DWT transformed digital image to get a random cipher image. To enhance the security level, a 14-bit LFSR is designed on Cyclone IV E, EP4CE115F29C7 FPGA board to generate the synthetic image. As the final stage of the algorithm, diffusion is performed based on XOR operation between the random cipher image and a synthetic image to get a final encrypted image. The designed image encryption algorithm is validated by performing statistical test, error metrics and key space analyses. The developed algorithm has achieved entropy equals to 7.9965; PSNR is 8.9903 which prove the algorithm is secure from the exhaustive attacks.