From 2 April 2014, it will adopt a simpler approach of three levels of security classification: OFFICIAL, SECRET and TOP SECRET.
Security classifications indicate the sensitivity of information and the need to defend against a broad profile of threats to it. Each classification will attract a level of security controls appropriate for managing the information risks involved.
The majority of information that is created or processed by the public sector. This includes routine business operations and services, some of which could have damaging consequences if lost, stolen or published in the media, but are not subject to a heightened risk profile.
Very sensitive information that justifies heightened protective measures to defend against determined and highly capable threat actors. For example, where compromise could seriously damage military capabilities, international relations or the investigation of serious organised crime.
HMG’s most sensitive information requiring the highest levels of protection from the most serious threats. For example, where compromise could cause widespread loss of life or else threaten the security or economic wellbeing of the country or friendly nations.