When transmitting secret or classified information, several stringent requirements apply to ensure its security and prevent unauthorized access:

Authorization and Recipient Verification

• The sender must have the authority to disclose the information based on government authorization or contract.
• The recipient must have a legitimate need to know, appropriate security clearance, and secure storage capabilities for the information.
• The sender must verify the recipient’s eligibility, facility clearance, classified address, and availability to receive the information, especially outside normal business hours

Secure Transmission Methods

• Classified information transmission must use authorized methods depending on classification level, with stricter methods for higher classifications (e.g., Top Secret requires the most secure methods).
• Collateral Secret information sent via USPS or commercial carriers must require a receipt signature upon delivery.
• Top Secret information must never be transmitted via USPS or commercial carriers

• Electronic transmission of classified information must be processed through authorized cryptographic systems approved by the originating agency

Encryption and Protocols

• Use strong encryption protocols such as SSL/TLS, IPsec, or SFTP to protect data in transit.
• Encryption ensures data confidentiality by turning readable data into an unreadable format without the correct decryption key.
• Multi-factor authentication and strict user verification (passwords, biometrics) are essential to ensure only authorized users access the data

Handling and Physical Security

• When transmitting physical media, use tamper-resistant packaging and reliable, authorized couriers.
• Procedures must include verifying courier identities, maintaining logs of dispatch and receipt, and ensuring correct addressing.
• Packaging should protect against damage from environmental factors like heat or moisture

Additional Security Measures

• Implement malware detection and prevention during electronic transmission.
• Prevent sending information to incorrect recipients by verifying addresses and contacts.
• Obtain prior authorization before using public communication services for transmission.
• Restrict or avoid using insecure communication methods like SMS or instant messaging for secret data.
• Advise personnel on risks associated with fax machines and other legacy communication tools

Compliance and Policy

• Follow applicable regulations such as NISPOM, DOD manuals, and agency-specific policies.
• Use the most cost-effective authorized method if multiple secure options are available.
• Maintain strict chain-of-custody and accountability throughout the transmission process

In summary, transmitting secret information requires authorized clearance, secure and approved transmission methods (often encrypted), strict recipient verification, physical and procedural safeguards, and adherence to regulatory policies to ensure confidentiality and integrity throughout the process.