It is well-known that organizations like the FBI, the US military and other key departments in the government hold many secrets. These secrets are actually a lot of sensitive data pertaining to each department procured by the people who work there. And some of this data just should not get out.
If important military data fell in the wrong hands, enemies would use this data against the country and will jeopardize the position of the country. Hence it is absolutely essential for all these departments to guard the data with utmost care and responsibility, to ensure the safety of its people.
This is where security clearance and its levels come in. They insure that no unauthorized person comes in contact with any information that he may not be authorized to view. It is natural to assume that some information is going to be more sensitive than others.
Hence all information is first classified under various heads and access is restricted based on this classification. This is the basis of creating security clearance levels. They ensure that only the right person gains access to the required information.
Levels of Security Clearance
It is convenient to classify the clearance level on the basis of the authority required for different levels of information as each level of information has its own security clearance requirements. Thus the different levels of information and the respective level of security for each is given here.
Unclassified Information: Level 0
Information under this head cannot be exactly said to be classified as it is the kind of information that is available to all. It can be released to the public at large without clearance. If identified to be as slightly sensitive, it will be first released to the law enforcement department, just for the sake of screening and then to common people.
Confidential Information: Level 1
The next security level would be to gain access to the information that is classified as 'confidential'. The information which can potentially damage national security is classified as confidential information.
Secret Information: Level 2
The next in the hierarchy of security levels, we have information that is classified as 'secret'. Most classified information will be held at this level. Such information is classified as secret, which if released, will seriously damage national security.
Top Secret Information: Level 3
Top secret information requires top level security clearance. It is such information that may cause exceptionally grave damage to national security. Very less information is actually classified as top secret.
Mostly, the information restricted to this level well be pertaining to weapon design, nuclear weapon related projects, presidential-security information, etc. Security clearance requirement for this level is understandably very stringent.
Another level is Compartmented Information. It's information is comparable to 'top secret', but restricted to a particular department. Hence if a person has access to compartmented information of one department, he may not necessarily have the authority to view the same of another department.
It is important to have such stringent and perfectly classified levels of security clearance in these turbulent times. After all, it is national security issue.