Part of a Series
System and Communications Protection: Securing Data for CMMC Compliance
Key Takeaways
System and Communications Protection (SC) is essential to safeguarding sensitive information during transmission and storage, starting at CMMC Level 2.
SC domain includes 16 mandatory practices at Level 2 focusing on encryption, monitoring, and access controls with additional enhanced controls at Level 3.
Proper documentation, validation of encryption standards like FIPS 140-2, and continuous monitoring are critical to successful compliance and passing assessments.
Introduction: Why System and Communications Protection Matters for Your Cybersecurity Strategy
In the rapidly evolving cybersecurity landscape, protecting data both while it travels across networks and when it sits quietly on devices has never been more vital. The System and Communications Protection domain, one of CMMC’s 14 core areas, ensures your federal contract information and controlled unclassified information remain confidential, intact, and resistant to unauthorized access or interception. Whether you're an IT director, compliance manager, or business operator managing defense contracts, understanding and implementing these controls can make or break your cyber readiness.
This blog breaks down what SC entails, its practical applications, and essential steps to ensure compliance with the standards outlined in 32 CFR Part 170 and NIST SP 800-171 R2. From encryption protocols to session management, you’ll gain actionable insights to strengthen your security posture.
For a broader understanding, explore our The 14 CMMC Domains Explained article or dive into connected domains like Access Control and Audit and Accountability to enhance your overall compliance strategy.
What Is the System and Communications Protection Domain?
In simple terms, the SC domain is about locking down your sensitive data from the moment it leaves one device to when it reaches another and throughout its rest on storage devices or servers.
Think of it as securely sealing a package before delivery and safely storing it in a secure vault thereafter. Failure here exposes critical information, such as defense blueprints or proprietary technologies, to interception by adversaries.
Real-world scenario: Imagine sending unencrypted blueprints via email. Should a malicious actor intercept these in transit, it represents a clear violation of SC principles.
This domain activates starting at CMMC Level 2 and is critical for any organization handling Controlled Unclassified Information (CUI).
How Many Controls Are Involved?
| CMMC Level | Number of SC Practices |
|---|---|
| Level 1 | 0 (Not applicable) |
| Level 2 | 16 mandatory controls |
| Level 3 | 16 controls + 4 enhanced controls |
Levels 2 and 3 require robust security measures, including additional advanced protections for Level 3 organizations as described in NIST SP 800-172.
Essential Practices to Secure Communications and Data
The SC domain covers a broad array of security practices to protect data confidentiality and integrity. Here are some key examples:
Monitor and control communications: Utilize firewalls, intrusion detection systems, and proxies to inspect and control network traffic.
Encrypt CUI in transit: Protect transmissions using TLS, VPNs, or equivalent encryption technologies.
Protect data at rest: Encrypt stored CUI on laptops, servers, and backups using FIPS 140-2 validated encryption.
Session management: Employ auto-logout and session token validation to maintain session authenticity.
Control mobile code and VoIP usage: Restrict and secure browser scripts, plugins, and voice over internet protocol communications.
These controls, when combined, create a multifaceted defense against interception, tampering, or unauthorized disclosure. Level 3 adds enhanced options like obfuscation and dynamic system isolation for increased resilience.
What Does Compliance Look Like for SC?
Meeting SC requirements demands not just technical implementation but thorough documentation and evidence gathering, including:
System Security Plans detailing how encryption and communication controls are deployed.
Network diagrams illustrating encrypted paths for CUI traffic.
Configuration snapshots of VPNs, TLS settings, and firewall rules.
Audit logs from data loss prevention tools demonstrating traffic monitoring.
Policies governing session timeout, mobile code, and device access.
Assessors will rigorously test encryption configurations and require demonstrable proof that CUI is securely handled both in transit and at rest. Without this, passing a CMMC audit is unlikely.
Our platform simplifies this process by automatically tracking encryption usage, logging compliance activities, and maintaining audit-ready artifacts so your team stays assessment-ready easily. If you want to streamline your compliance efforts, consider signing up for our CMMC dashboard for comprehensive tracking and audit preparedness.
Common Pitfalls and How to Avoid Them
Many organizations stumble over these recurring issues:
Assuming standard HTTPS usage provides full compliance without vetting internal applications.
Encrypting sensitive files but mismanaging encryption keys by storing them unprotected.
Employing outdated or non-FIPS validated cryptographic algorithms.
To avoid these traps:
Use only FIPS 140-2 validated encryption modules.
Implement automated policies for session timeouts and access revocation.
Encrypt all backups and removable media.
Regularly validate firewall rules to ensure default-deny stance.
Clear policies paired with technical rigor deliver resilience against common loopholes.
Conclusion: Making System and Communications Protection a Cornerstone of Your Security Posture
The System and Communications Protection domain acts as a critical shield, defending your CUI against interception, tampering, and unauthorized distribution. With 16 foundational controls at Level 2 and more sophisticated requirements at Level 3, effective SC practices ensure your defense supply chain commitments meet federal standards.
Start by auditing each SC practice within your scope, updating policies, and configuring your systems accordingly. Our CMMC dashboard can streamline your compliance tracking and artifact management, simplifying audit readiness so you can focus on securing your enterprise.
“Organizations must protect the confidentiality of CUI in transit and at rest through the use of cryptographic methods compliant with FIPS 140-2.”
— NIST SP 800-171 Revision 2, Requirement 3.13.8
Quick FAQs for SC Domain
Q: Does the SC domain apply at CMMC Level 1?
A: No, SC controls kick in starting at Level 2, focused on CUI protection.
Q: Is deploying SSL/TLS enough to secure data in transit?
A: Only if TLS is properly configured with current cipher suites, managed securely, and validated per FIPS 140-2 standards.
Q: What about cloud environments?
A: Cloud providers must comply with FedRAMP Moderate baselines and use FIPS 140-2 encryption to protect your CUI adequately.
Ready to enhance your System and Communications Protection controls? Start tracking your progress today with our CMMC dashboard and stay ahead of compliance challenges effortlessly.
Sources
National Institute of Standards and Technology, Special Publication 800-171 Revision 2
National Institute of Standards and Technology, Special Publication 800-172
Code of Federal Regulations, Title 32 Part 170
Department of Defense CMMC Assessment Guide Level 2