NIST SP 800-171: Securing Controlled Unclassified Information (CUI) on Digital and Non-Digital Media

As government contractors, defense suppliers, and organizations handling Controlled Unclassified Information (CUI), compliance with NIST Special Publication (SP) 800-171 is not optional, it’s a contractual requirement. Failure to meet these standards can lead to significant business disruptions, loss of contracts, and reputational damage.

One of the core pillars of NIST SP 800-171 is Media Protection, which ensures that CUI stored on both digital and non-digital media is properly safeguarded throughout its lifecycle, from creation to transport and eventual disposal. This article breaks down the key requirements of Media Protection and offers practical strategies for compliance.

Key Media Protection Requirements

The Media Protection family, detailed in section 3.8 of NIST SP 800-171, defines the standards for handling CUI on various forms of media, including hard drives, USBs, printed documents, and backup tapes. The goal is to prevent unauthorized access, leakage, or reconstruction of sensitive information.

• Secure Storage and Physical Control (3.8.1). Organizations must physically secure and control access to CUI media. This includes both digital and non-digital formats. Best practices involve:

  • Locking storage areas: Store physical media (e.g., backup tapes, printed documents) in locked cabinets or safes.

  • Limiting access: Only authorized personnel should handle CUI media, with access logged and monitored.

  • Regular inventories: Conduct periodic audits to ensure media is accounted for.

• Restricting Access to Authorized Users (3.8.2). To prevent unauthorized retrieval, only approved individuals should access CUI media. Organizations should:

  • Implement check-in/check-out procedures for physical media.

  • Use access logs to track when and by whom media is accessed.

  • Monitor secure storage areas with surveillance systems.

• Sanitizing or Destroying Media Before Disposal or Reuse (3.8.3). Before media containing CUI is discarded or repurposed, it must be thoroughly sanitized or destroyed to prevent data recovery. Methods include:

  • Data wiping: Overwriting storage devices with multiple passes of random data.

  • Degaussing: Using a strong magnetic field to erase data on magnetic storage.

  • Physical destruction: Shredding, disintegrating, or pulverizing storage media.

• Proper Marking of CUI Media (3.8.4). Media containing CUI must be clearly labeled to indicate its sensitivity level and distribution limitations. Labels should comply with federal regulations and policies, making it easy to identify and protect CUI appropriately.

• Controlled Transport Outside Secure Areas (3.8.5). When CUI media leaves a controlled environment, it must remain secure during transport. To achieve this:

  • Use locked containers and tamper-evident seals.

  • Only allow authorized couriers to handle and transport CUI.

  • Maintain detailed transport logs to track the media’s movement and detect anomalies.

• Cryptographic Protection During Transport (3.8.6). To safeguard CUI during transit, organizations should implement cryptographic controls unless alternative physical safeguards are in place. Encryption ensures that even if the media is intercepted, the data remains protected.

  • Portable storage encryption: Encrypt data on USB drives, DVDs, and external hard drives.

  • Encryption keys: Protect encryption keys with strict access controls and multi-factor authentication (MFA).

• Controlling the Use of Removable Media (3.8.7). Removable media, such as USB drives, pose a significant risk of data exfiltration and malware infection. Organizations should:

  • Restrict usage: Limit the use of unapproved removable media devices.

  • Enable read-only access: Prevent users from copying sensitive data onto external drives.

  • Implement port blocking: Disable unused USB and external drive ports.

• Prohibiting Untraceable Portable Storage Devices (3.8.8). To maintain accountability, organizations must prohibit the use of portable storage devices with no identifiable owner. This practice enhances traceability, reduces insider threats, and simplifies investigations if a device is lost or compromised.

• Protecting Backup CUI at Storage Locations (3.8.9). Backups containing CUI must remain secure even in storage. Organizations can use encryption at rest to protect backup data, limit physical access to backup storage locations, and regularly audit backup integrity and access controls.

Best Practices for Media Protection Compliance

To effectively implement NIST SP 800-171’s media protection requirements, organizations should adopt the following best practices:

• Comprehensive Policies and Procedures: Establish detailed policies governing media handling, transport, and disposal. Clearly define roles, responsibilities, and approved procedures.

• Technical Controls: 

  • Port blocking: Disable ports that support removable media to prevent unauthorized use.

  • Device allow-listing: Only permit authorized removable media devices on the network.

  • Encryption enforcement: Use automatic encryption policies for portable media.

• Training and Awareness: Regularly train employees on the risks associated with removable media, proper handling procedures, and the consequences of policy violations.

• Regular Audits and Testing: Conduct routine audits to verify compliance with media protection controls. Perform penetration tests to identify vulnerabilities in media handling processes.

Ensure Your Compliance with Total Assure

At Total Assure, we specialize in helping organizations meet NIST SP 800-171 compliance requirements with robust cybersecurity strategies. Our experts develop tailored media protection policies, implement encryption and access controls, and conduct readiness assessments to identify and close security gaps.

Partner with us to strengthen your compliance posture and safeguard your sensitive data. Contact Total Assure today to schedule a consultation and take the next step toward securing your organization’s CUI.