Results of modeling different schemes of the spatial orientation and scanning series of base blocks of images to confront an unauthorized extraction of steganographic data

Abstract

This work presents the results of modeling attempts at unauthorized extraction of steganocontent (halftone test images) under the condition of selective compromise of each of the two active processing parameters of the source array series of base blocks (BB) of content, i.e.: - the scheme scanning of BB series and the spatial processing of BB. The current program version ensures consistent realization of the main stages of content processing with the necessary settings parameters. As part of the modeling, it is suggested that the attacker has correctly identified one of the two current content processing parameters. Several modifications of the main schemes scanning of BB series and the spatial orientation of BB (rotation and horizontal mirroring) as an additional mechanism to counteract attempts of illegitimate content extraction are considered. The modeling was conducted on the examples of three types of images: - portrait, landscape, and mnemonic scheme. Manipulations with the spatial orientation parameter of BB strengthen the opportunities to counteract attempts at unauthorized data extraction. Characteristic quantitative and time histograms for different dimensions BB of content, changes in the peak of value signal-to-noise ratio for different types of schemes scanning BB series are presented, and samples of attacked test images are presented. The analysis and generalization of the main differences in the attack results using different parameters of the spatial processing of BB and ways of scanning series of BB of image-content are performed. Attention is drawn to the fact that the use of two active processing parameters of the source array of BB series is an effective and computationally «simple» means of counteracting attempts at unauthorized data extraction. The relationship between the stage of preprocessing the source content and the parameters of the formed arrays BB is emphasized. It is concluded that the introduction into the structure of the data extractor key, the elements of «The state of scanning» and «The spatial processing of BB», strengthens the overall capabilities to counteract attacks. The used processing parameters of the source array of BB series determine the structure of visual artifacts of attacked images but do not produce a simple solution to identify the attacked image at the level of classifying the type of source images. Prospective directions for further modeling of the main protection mechanisms within the proposed algorithm concept are indicated.