Classified information is confidential material that a government, corporation, or non-governmental organisation deems to be sensitive information, which must be protected from unauthorized disclosure and that requires special handling and dissemination controls. Access is restricted by law, regulation, or corporate policies to particular groups of individuals with both the necessary security clearance and a need to know.
Classified information within an organisation is typically arranged into several hierarchical levels of sensitivity—e.g. Confidential (C), Secret (S), and Top Secret (TS). The choice of which level to assign a file is based on threat modelling, with different organisations have varying classification systems, asset management rules, and assessment frameworks. Classified information generally becomes less sensitive with the passage of time, and may eventually be reclassified or declassified and made public.
