SPEECH INFORMATION CRYPTOGRAPHIC PROTECTION METHOD BASED ON DIFFERENTIAL TRANSFORMATIONS

The problem of information security that circulates in communication channels is constantly being updated. It is especially acute for military VoIP telephony or dual use. This relates to the growth of the value of confidential information, which is of interest to cybercriminals, and with the increase in the technological complexity of cyberattacks at the same time as the productivity of technical means of obtaining unauthorized information increases. Cryptographic methods of information protection occupy one of the key places among the well-known mechanisms for ensuring the cyber security of speech information circulating in communication channels. SRTP security protocols, which implement the symmetric cryptographic encryption algorithm AES, are most often used to organize secure VoIP traffic. At the same time, the potential compromise of the best symmetric cryptographic algorithm AES-256 requires the search for new non-trivial approaches to improving cyber security mechanisms. One of these approaches developed in the article is an approach based on the use of the Fredholm cryptosystem model. The mentioned cryptographic system belongs to the class of symmetric cryptographic systems, but to date, due to the lack of scientifically based cryptographic algorithms, it has not yet gained practical implementation. To resolve this contradiction, the article, based on the principle of O. Kerckhoffs, developed a method of cryptographic protection of speech information based on differential transformations developed by Academician of the National Academy of Sciences of Ukraine H. Pukhov. The developed method makes it possible to obtain a cipher in the form of a differential spectrum, which is resistant to known methods of cryptanalysis. The article developed an algorithm for implementing the method. The results of encryption and decryption of speech information are given. The convergence of simulation results with other known methods confirms the workability of the developed method.