Yevgen Radchenko

Background. Classical steganographic data protection is based on hiding the fact of secret data existence. Until this fact is disclosed, the data remains protected. However, in most of the cases, such protection is insufficient for ensuring data security. Therefore, it is common practice to combine data encryption and steganographic embedding. Recently, this approach has been used in many fields of application, including the protection of e-commerce transactions. Thus, the task of developing new, more complex methods of crypto-steganographic data protection remains topical. Objective. The main goal is to protect the user's multimedia data by using a composite private key to limit access to this data. To achieve this goal, the research objective is to develop a steganographic method for protecting multimedia data by embedding it in pseudo-random samples of an audio file. Methods. The proposed method is a method of combined crypto-steganographic data protection. It is based on the use of a composite private key. The method uses two pseudo-random number generators. The first generator is used in the procedure of secret data block mixing. The second generator is used in the steganographic embedding procedure to select the next sample for embedding secret data. The steganographic embedding of secret data is carried out according to the principle of bits correspondence using the result of logical operations. The method uses the natural properties of audio data, namely, their redundancy. Results. A method for steganographic protection of multimedia data based on the pseudo-random embedding procedure has been developed. It includes three main stages. At the first stage, preliminary data preparation is fulfilled. At the second stage, the secret data block arrangement order is formed to be used while embedding. At the third stage, the steganographic embedding of secret data into the container is carried out. The proposed data processing procedures enable increasing the level of protection due to pseudo-random mixing and embedding the data.Conclusions. The developed steganographic method for protecting multimedia data uses audio data as a container for secret data steganographic embedding. It includes data processing procedures based on pseudo-random number generation algorithms. An analysis of the proposed method resistance to unauthorized access to hidden data has shown that the probability of the steganographic scheme guessing is small. The proposed method can be used in cases where steganographic protection is considered as more appropriate than cryptographic protection.