What is a key factor in determining access to classified information?

The key factor in determining access to classified information is the security clearance level and the principle of need-to-know. Security clearance levels are established based on an individual's background investigation and are assigned based on their role and responsibilities; these levels determine the types of classified information that an individual is authorized to access.

The need-to-know principle further refines access by ensuring that only those individuals who require specific information to perform their job duties are granted access to it. This means that even if someone has a high-level security clearance, they must still demonstrate a legitimate need for the information to be allowed access. This dual requirement of both clearance and need-to-know is essential for safeguarding sensitive information and is a cornerstone of information security protocols within organizations handling classified data.