Narimanova O. Method of checking the digital signal integrity

The object – the process of digital signals analysis at the integrity violation. The subject – features of DCT coefficients histograms of digital signal. Research methods: signal processing and number theory to analyze the exhibition of the double quantization effect, mathematical analysis to improve the mathematical model of print-scan process for a digital image, discrete mathematics to the study of graphs algorithms, vector analysis for the study of vectors of initial conditions. Theoretical and practical results: for the first time a criterion for the exhibition of the double quantization effect for digital signal is formulated and proved, it became the theoretical basis of the applicability of the method of checking the digital signal integrity and method of forgery area better localization for digital signals; for the first time under the double quantization effect the method of checking the digital signal integrity is developed, it allows to verify the digital signals integrity regardless of the form of their presentation; for the first time under the double quantization effect the method of forgery area better localization is developed, it allows to localize the forgery area with low sizes; for the first time the conditions of construction of the vectors of initial conditions that satisfy the specified characteristics and provide the shortest time implementation of the algorithm in its implementation on a multiprocessor computer system are obtained. The thresholds for the separation of the negative contribution of natural noise from the negative contribution of falsification are obtained, their use will increase the degree of detection the violations of digital signals integrity. The method of virtual increase of the contribution of forgery area into a digital signal is developed, its use has increased the security level of information objects and reduce the response time to violations.