Secure Satellite Images Transmission Scheme Based on Chaos and Discrete Wavelet Transform

Many applications based on satellite communication like national defence and security rely on the satellite images as an important source of information. It is therefore, mandatory to secure satellite imagery while transmitting them over communication channels to protect from unauthorized access and usage. In this paper, chaotic logistic map based satellite image encryption scheme is proposed to meet the requirement of secure satellite-based communication. The algorithm is based on the concept of permuting the pixels of satellite image, then improving the pixels gray value distribution from cryptographic viewpoint. The permutation of image pixels is carried out in discrete wavelet domain and the relationship between the encrypted and the original satellite image is confused using chaotic-state modulation technique, thereby significantly increasing the resistance to statistical attacks. Experimental results demonstrate that the scheme has the advantage of high sensitivity to secret key and large key space. Moreover, the encrypted satellite images have uniform gray level distributions, high entropies and low correlation coefficients. Hence, the theoretical and experimental analyses confirm that the proposed scheme has high security and can be applied for practical satellite image protection.