Review

The article provides a comprehensive study of the theoretical, regulatory, and practical aspects of the use of digital evidence in criminal proceedings concerning criminal offenses against the fundamentals of Ukraine’s national security. In the context of escalating hybrid threats, intensified intelligence and subversive activities, and the growing use of secure digital platforms, digital evidence has become the dominant source of factual information. The study examines the nature of digital data, its differences from traditional physical and documentary evidence, as well as specific characteristics related to its immateriality, volatility, and dependence on technical environments. Doctrinal approaches to the understanding of electronic evidence are analyzed, including the views of Ukrainian scholars concerning the criteria of authenticity, integrity, immutability, and trace-ability of digital data. The role of operational-search activity and covert investigative (search) actions in generating digital evidence is explored, taking into account the specificities of their use in proceedings involving elevated secrecy and risks of counteraction by subjects engaged in criminal or hostile activity. Considerable attention is devoted to judicial and prosecutorial mechanisms of controlling the legality of interference with an individual’s private sphere, assessing the compliance of procedural practices with the standards of the European Court of Human Rights, as well as the role of the defence in ensuring the reliability of evidence and in verifying the admissibility of covertly obtained materials. Based on the findings, the article outlines the need to improve national legislation, standardize technical procedures for handling digital evidence, and develop a specialized evidentiary model for cases related to national security. It identifies promising directions for further research, including enhancing the reliability of digital forensics, ensuring a balance between secrecy and the right to defence, and integrating international standards into national legal practice.