± 1Highly Undetectable Stegosystem Model Using Digital Still Images

This article presents a model of a highly undetectable stegosystem using digital still images as covering objects. The main principle of using the model is to minimize adequately specified distortion using an effective encoding algorithm. Distortion is defined as an operation ± 1 on a specially selected image (covering object) byte which is selected from the condition of minimizing the penalty function calculated on some selected neighborhood of this byte. This allows us to preserve the original image in almost unchanged form and make it indistinguishable even after the introduction of large payloads. Thus, the embedded hidden message may not be visible at steganalysis even for the experienced steganalytic. The stegosystem model was named ±1 Highly Undetectable SteGOsystem model. In short, it can be designated as ± 1HUGO model [10]. This model can be implemented to embed hidden messages in the spatial domain of digital still images much more efficiently than using the LSB algorithm. The proposed stegosystem model provides higher performance than the LSB algorithm and allows you to send a longer message, while providing higher resistance to detection.