Digital Images Encryption in Frequency Domain Based on DCT and One Dimensional Cellular Automata

We are living in an age where security of digital information like digital images is becoming more important in many aspects and the tranmission of digital images is increasing over the internal and international computer networks. The protection of digital images from unauthorized access is the main purpose of this paper. This paper introduced an approach to encrypt a digital image in frequency domain through DCT (Discrete Cosine Transform) and one dimenssional cellular automata. It is based on encryption of some quantified DCT coefficient in high frequencies. We applied our proposed model on one hundred numbers of JPEG grayscale images of size 800 x 800. The experimental results have indicated the robustness of our algorithm.