An approach for security of color image data in coordinate, geometric, and frequency domains

This article presents a novel cryptosystem for secure transmission of color images through a coordinate cryptosystem as well as a geometric cryptosystem with time domain and frequency domain. In this technique, we have designed image encryption and decryption by a proposed random matrix shift cipher (RMSC) associated with a discrete fractional Fourier transform (DFrFT). Our proposed random matrix shift cipher is a coordinate and geometric cryptosystem for security of color image data which is completely different from existing cryptosystems for security of any data. The combination of a random matrix shift cipher and discrete fractional Fourier transform provide a robust cryptosystem for color image data in the time domain as well as the frequency domain without loss of any information. Existing techniques provide single-layer protection of color image data, but the cryptosystem presented here gives multiple layers of protection. Computer simulation on a standard example (Lena and Barbara color images) and the result are support for the robustness and appropriateness of the proposed cryptosystem.