Methods authorized for transmitting top secret documents include the following:
- Direct contact between authorized persons.
- Defense Courier Service (a specialized secure courier service).
- Department of State Diplomatic Courier Service.
- Cleared designated couriers or escorts.
- Secure communications systems approved by the Cognizant Security Agency (CSA).
- The United States Transportation Command (USTRANSCOM) when authorized.
Notably, common commercial services such as USPS Express or Registered Mail are generally not authorized for top secret material transmission, but they may be used for secret-level documents in some cases. Top secret transmission requires stringent controls such as using cleared personnel, specialized courier services, or CSA-approved secure communication circuits to ensure the highest level of security protection for such highly sensitive documents.
