1. The prescient defense
Frank Herbert’s Dune returns as the recalled work because the Bene Gesserit and the Mentats train themselves to see patterns before they become obvious. Spacecraft cybersecurity is similar: the literature is not about preventing a single known attack but about building a posture that anticipates where the next attack will come from and containing it before it reaches the mission-critical layers.
Entries 677 through 679 read about spacecraft cyber threats and attack vectors, secure command authentication and link protection, and onboard protections. This entry closes the arc.
2. What was learned
The cybersecurity literature gives the desktop four constraints:
- Risk concentrates at accessible interfaces. Communications and ground segments have the highest severity scores; onboard computing benefits from orbital isolation but is not immune.
- Authentication beats encryption in priority. A forged or replayed command does not need to be decrypted to cause harm; the command link must authenticate origin and freshness.
- Power constrains cryptography. Elliptic-curve methods are generally more efficient than RSA for small-satellite-class platforms; terrestrial defaults may be too expensive.
- Defense must be layered. Link authentication, secure boot, bus segregation, least privilege, selective logging, and anomaly detection each cover failures of the others.
3. What was decided
The desktop will adopt a layered, power-proportionate cybersecurity posture with these baseline commitments:
- All command uplinks will be authenticated and replay-resistant.
- Telemetry and command content will be encrypted with algorithms chosen for power efficiency.
- Software and firmware updates will be cryptographically signed and verified.
- Critical and non-critical subsystems will be segregated and granted least privilege.
- Critical events will be logged in a cyclic buffer and downlinked opportunistically.
- Anomaly detection will be evaluated as a supplementary layer, with rule-based fallbacks for safety-critical decisions.
4. Interaction with earlier arcs
The cybersecurity reading arc connects directly to:
- the autonomous orbit maintenance arc: collision avoidance maneuvers must be authorizable without ground contact;
- the autonomous power budgeting arc: load shedding and safe mode must not be triggered by forged commands;
- the software update arc: secure updates depend on signing and verification;
- the command authentication test arc: the next test will verify that the protections work.
5. What remains open
The exact cryptographic algorithms, key rotation schedule, hardware root of trust implementation, and anomaly-detection model depend on the final onboard computer, radio, and power budget. The reading arc has set the strategy; detailed design comes later.
6. What this changes
- The cybersecurity reading arc is closed.
- The desktop inherits a layered, power-proportionate cybersecurity posture.
- The next arc will wonder about autonomous trust boundaries and secure maneuver authorization.