Final answer:
The authorization for couriers to carry classified materials on commercial transport is provided by government agencies. These couriers, who must have the necessary clearances, are guided on handling classified material and interacting with airport security.
Step-by-step explanation:
The authorization for the hand carry of classified materials on commercial flights or other means of transport is typically provided by government agencies responsible for national security. This can include various departments within the government such as the Department of Defense or any other agency with jurisdiction on classified information. The individuals who are granted authority to transport classified materials are often referred to as couriers, and they must possess the appropriate security clearance to handle such sensitive items.
Couriers are thoroughly briefed and understand the procedure for communicating with airport personnel and security to ensure the safe and secure transit of classified materials. Special authorizations might be required, and couriers are often instructed on how to navigate situations where they might trigger radiation detectors or other security measures at airports, due to the nature of the materials they're transporting.
It is important to note that the right of the press to print classified material is not absolute. The Supreme Court has ruled that the press may only print classified material if it does not compromise the safety of troops or covert operatives.