A Novel Approach for Transmitting Secret Data Based on Chaotic Map and Spread Spectrum Watermarking in Frequency Domain

Given the ever-increasing applications of the Internet and the growing volume of exchanged information, preserving the security and authentication transmitted images (that may have business, military, or even medical applications) are also gaining importance by the day. In this paper, we have proposed a robust watermarking algorithm for the protection and authentication of medical images in which the capabilities of chaotic maps have been utilized. The scheme obtains the feature vectors of the host image using discrete wavelet transform (DWT) and discrete cosine transform (DCT). The watermark image is encrypted by modified logistic map, and the initial conditions of the chaotic map used are embedded as a key in the frequency coefficients of the original image in the form of a spread spectrum to increase the security of the algorithm. Simulation results show that the proposed method has high security and robustness against image processing.