Research on Potentialities of Audio Information Recovery from Video Without Audio Track

The article analyzed the possibility of the appearance of an acoustic information leakage channel that is formed by analyzing the video stream on the video record. The authors investigated the possibilities of speech recovery from a low quality recording, determined by the signal-to-noise ratio (SNR), sampling frequency, number of quantization levels, and clipping level, taking into account the features of the leakage channel under study. As a result, the required frame rate of the video image, the minimum SNR, the number of quantization levels, and a sufficient dynamic displacement range of the oscillating object are determined. The authors also investigated the requirements for the leakage channel parameters and possible ways for an attacker to improve its quality. The requirements for the displacement of an object oscillating under the action of acoustic waves in a video were calculated. The article justified the potential of reducing the requirements for the displacement of an object by applying averaging of a large number of different points on the object. The authors performed an assessment of the existing noise reduction software for sound recordings, which is used to increase the intelligibility of the message that is intercepted by the attacker in the considered information leakage channel. Obtained results revealed that there are potential causes for the leakage of acoustic information by analyzing the video stream on the video. The conditions for the emergence of such a channel are not excessive. Therefore, the possibility of its appearance is a security risk and it is necessary to provide the means to protect the object of information activity from it. © 2019, Allerton Press, Inc.