Abstract:  With the increase of awareness on the problems of national security associated with the unauthorized disclosure of classified information, the legal protection of classified information obtained a new meaning. However, it simultaneously causes growing concern regarding its impact upon the freedom of information. Between these competing political interests lies a separate branch of law, which defines and protects specially designated secrets from unauthorized disclosure. The goal of this article consists in determination of the relevant state practice for protection of classified information for national security reasons in various countries, as well as consideration of the general problems of demarcation of the grounds of national security for protection of classified information in light of changing circumstances of national security. The study explores 108 countries, in which the State Secrecy Law exists in one or another form from the perspective of: 1) classification of information on national security; 2) threshold values of disclosure; 3) offences related to disclosure of classified information. The conclusion is made that with the expansion of modern “state of national security”, the existing legal criteria would become less and less efficient in demarcation of the grounds of information security for protecting specially designated secrets, if the legislation does not clearly place public interest before the interests of national security.