SC-8(3) - Transmission Confidentiality and Integrity | Cryptographic Protection for Message Externals

Implement cryptographic mechanisms to protect message externals unless otherwise protected by [Assignment: organization-defined alternative physical controls].


ID: SC-8(3)
Enhancement of : SC-8

Space Segment Guidance

Protecting message externals—like routing headers and address fields—via cryptography (or obfuscation) thwarts adversaries who try to glean routing intelligence or track transmissions. On an orbiting asset that uses network-like protocols—mainly fractionated satellites that route data through cross-links—such envelope protection helps conceal topologies and node identities. For example, packet headers can be encrypted with NSA-approved algorithms, reducing the chance that an eavesdropper can map out mission-critical links. This secures data privacy and operational security: by hiding who is talking to whom and how often, the spacecraft complicates an adversary's efforts to target key nodes. Especially under CNSSP №12 guidelines, robust TRANSEC measures combine with cryptographic header protection to offer holistic defense against traffic analysis and intelligence gathering.