Visual Cryptography Technique Based on FFT

Abstract

Visual cryptography is a powerful approach for image sharing security through unsecured network such as Internet. Pixel expansion and bad image quality are the most cons of this approach. Therefore, visual cryptographic technique is proposed for grayscale images to overcome these drawbacks by Fast Fourier Transform (FFT). FFT is used for image sharing where each share is encrypted via Multilayer Security Method (MSM). Image compression is also basically used to eliminate the pixel expansion which is produced before the encryption process. The experimental results and security analysis state that the proposed visual cryptographic technique leads to active levels of image security and quality without pixel expansion.