Kleptography in information security context. Classification of kleptographic attacks

The increasing informatisation of society presents new challenges, as modern information technologies are used not only by regular users but also by individuals engaged in illegal activities, such as criminals, fraudsters, and terrorist groups. These technologies are being exploited for unlawful operations, which requires each state to maintain control over its segment of cyberspace. The issue of exclusive access and control by specialised services over citizens' information activities is becoming increasingly important as the level of informatisation increases. A key challenge in this area is that kleptography, as a discipline that studies this field, is still in its early stages and is often applied in a rather narrow sense. An analysis of existing works on this topic has shown that kleptography is still predominantly viewed in the context of cryptography, which provides a narrow and specific perspective on this discipline. The problem of identifying secret channels for information leakage needs to be considered beyond traditional cryptanalysis, as in the current era of widespread digitalization and informatization, attackers are finding increasingly sophisticated ways to carry out illegal information activities. The purpose of this article is to present kleptography in a broader context than cryptography and to provide a classification of kleptographic attacks. This study examines kleptography in the modern context, its tasks and challenges, and offers a classification of attacks based on hidden channels. The results show that kleptography has evolved from research focused on cryptographic backdoors to a broader understanding of information security threats. The primary idea of kleptographic attacks is to introduce vulnerabilities during the system's development or operation stages, using hidden channels to leak data. Kleptography encompasses not only cryptography but also hardware and software security, including side-channel attacks such as power consumption or timing analysis. Detecting such attacks is challenging and requires a comprehensive approach that integrates cryptanalysis, engineering, and analysis of physical system processes.