Encryption in Transit

Encryption in transit protects data as it moves across networks — between your systems, to cloud services, over VPN connections, via email, and to external parties. It prevents anyone intercepting network traffic from reading the encrypted content. TLS/SSL is the most common protocol for encrypting data in transit.

For CUI, all network paths where CUI travels must be encrypted using FIPS-validated cryptography. This includes internal network traffic between CUI systems, not just external connections. Common implementations include TLS 1.2+ for web traffic, IPsec VPNs, and S/MIME for encrypted email.