Multi-layer security of color image based on chaotic system combined with RP2DFRFT and Arnold Transform

The security system for RGB image information is very critical issue in current time. In this security system, we have proposed an algorithm for encryption and decryption of RGB images by using chaotic system based scrambling combined with reality preserving two dimensional discrete fractional Fourier transform (RP2DFRFT) and Arnold transform (AT). Earlier developed security system for RGB image data provides only one layer of protection either in time domain or in frequency domain. But presented cryptosystem provides multi-layer security for RGB image in time as well as in frequency domain with no loss of any information of red (R), green (G) and blue (B) components. The algorithms of existing techniques for the security of color images are mostly based on keys, but the proposed cryptosystem provides security of color images on the basis of the keys as well as the arrangement of used algorithms and parameters. Additionally, the use of reality preserving method not just eliminates the complexity of dealing with imaginary data, but it also enhances the efficiency of the technique by reducing the domain space to its half, at least for all the calculations involved in two dimensional DFRFT. The sensitivity analysis of the proposed technique represents that the encryption keys are very sensitive. Results on standard examples and their security and statistical analysis for color images are testimony to the robustness and appropriateness of the presented technique. This method would find a large applications in digital color image processing and security of color image transmission in open network.