Annotation: This article describes a simulation software designed to conduct research on highly undetectable stegosystems (so-called HUGO systems), the purpose of which is to increase the efficiency of the stegosystem with respect to the undetectability of hidden messages, provided they are transmitted in communication channels with a high noise level. To achieve this goal, this paper solves the problem of developing a software package that performs on the sender's side discrete chaotic transformation of a secret message, then embedding it into a covering object using the ±1HUGO method and encoding, and on the recipient's side decoding using a multi–threshold decoder, extracting a secret message and reverse discrete chaotic transformation. In addition, the software package must calculate performance indicators: the peak signal-to-noise ratio and the Pearson correlation coefficient of the covering object and the stego.

Keywords: ±1HUGO, stegosystem, self-orthogonal noise-tolerant code, multi-threshold decoder, discrete chaotic transformation, Arnold Cat Map transform, chaotic baker mapping.