The article presents a method for protecting transmitted images in instant messengers using time-based one-time passwords (TOTP). An additional level of protection is offered based on a combination of image masking using orthogonal matrices and two-factor authentication based on TOTP. A prototype Python application has been developed and tested using the gRPC remote procedure protocol to ensure secure data exchange between the client and the server. The results of the implementation of the proposed method in preventing unauthorized access to confidential images are presented.

Keywords: information security, messenger, messaging, communications, instant messaging systems, one-time password

This article examines the vulnerability associated with storing image files in the cache on the device's hard disk in unencrypted form. The nature of this problem and the possible consequences of its exploitation, including leakage of confidential data, abuse of information received and risks to corporate information systems, are being investigated. The main attention is paid to the method of protection against this vulnerability, which is based on the use of masking techniques using orthogonal matrices.. The developed prototype of the messenger is presented, in which this method is implemented: images are transmitted and stored in the file system in masked form, the unmasking process is carried out directly in the messenger application itself.

Keywords: information security, messenger, messaging, communications, instant messaging systems, encryption, orthogonal matrices