A method of steganographic message transformation with the partial antidisturbance property

Разработан новый метод стеганографического преобразования двоичного сообщения, который позволяет внедрять в него скрытые данные. Для минимизации искажений статистических свойств контейнера, вносимых при внедрении, предложено преобразовывать сообщение, взятое из пустого контейнера. Алгоритм используется непосредственно перед применением стеганографического метода внедрения. Преобразование позволяет противодействовать методам стегоанализа, базирующимся на изучении статистики извлеченных из контейнеров сообщений. При использовании указанного алгоритма стегоаналитик не может корректно извлечь до 32% бит сообщения из контейнера, и соответственно, реализовать эффективный стегоанализ. Объем внедрения скрытых данных составляет 19% от длины исходного сообщения. В работе рассмотрены различные алгоритмы стегоанализа текстовых данных, показана их низкая эффективность после применения нового метода. Purpose. This article addresses the development of a new method for embedding hidden messages in various containers (text, executable files). Methods. During this research the methods of information theory, probability theory and mathematical statistics are used. Efficiency analysis of the new method was carried out by using the Chi-square test. Results. A new method of steganographic transformation of a binary message, which allows to embed hidden data is presented. It is proposed to transform a message taken from an empty container. The original message is considered as a set of twobit elements. A sequence of non-repeating elements, called series, is used to embed a secret message. Embedding was performed by permutations of elements within the series. The proposed algorithm allows simulating statistical features of a message taken from an empty container, which reduces the probability of successful stegoanalysis. A stegoanalyst who does not know some secret parameter cannot correctly extract the message from the suspicious container and analyze its statistical properties. Thus, the steganalysis approach, based on detection statistical differences in a message taken from an empty and filled container, becomes ineffective. Conclusions. The new method of steganographic message transformation of an empty container allows embedding hidden information, with minimal distortion of the statistical properties of the original container. In the course of the experiment statistical properties of the message taken from container before and after embedding were investigated. The analysis was carried out using previously known methods of steganalysis, based on detecting statistical differences in messages taken from empty and filled containers. It is shown that without knowing a certain secret parameter, the stegoanalyst cannot correctly extract up to 32% of the message bits from the container, which leads to significant errors in the stegoanalysis. The volume of the message being embedded is 19% of the length of the original message in the empty container. The algorithm presented in this paper is recommended to employ for embedding into containers: text, audio, executable files, graph containers. Using of this algorithm for images is not accounted for.