Abstract
This paper examines the risks posed by passive surveillance of deep-space command and control protocols. Through theoretical analysis and protocol modeling, it demonstrates how long-term sniffed data collection can lead to the reconstruction of spacecraft command timing, state transitions, and sequence logic. The paper concludes that modern space missions must implement encrypted and authenticated command uplinks to maintain operational security against increasingly capable adversaries.
1. Introduction
Most space missions, particularly civilian deep-space probes, rely on unencrypted command uplinks. These systems have traditionally depended on the physical difficulty of signal injection and protocol complexity to deter interference. However, this approach assumes attackers lack
access to long-term observational data or sophisticated analytical capabilities—an increasingly dangerous assumption.
2. Threat Model and Assumptions
The adversary is capable of passively collecting deep-space communication uplinks, possibly from orbit or near-Earth interception points. No prior access to the spacecraft or source systems is assumed. The spacecraft employs basic protocol validation: sequence counters, timestamps, CRCs, and command whitelists, but lacks cryptographic protection.
3. Attack Phases
3.1 Phase 1: Passive Surveillance
Sniffed command packets over time reveal packet structures, command IDs, sequence patterns, and timestamp formatting.
3.2 Phase 2: Pattern Analysis with AI/ML
By training models on the observed packet data, adversaries can predict system state transitions, expected command types, and uplink timing windows.
3.3 Phase 3: Payload Fogery
Crafting valid command packets with predicted sequence numbers, plausible arguments, corrected timestamps, and valid CRCs.
4. Defense Mechanisms and Their Limits
Traditional defenses such as timestamps, sequence checks, and command whitelisting fail under prolonged observation. If adversaries can reconstruct mission state and command flow, they can bypass protocol-layer defenses.
5. Probability Analysis
Blind guessing results in a 1 in 10^18 chance of command success. Sniffing reduces the entropy, possibly down to 1 in 10^7 or better. AI-assisted prediction further reduces these odds by orders of magnitude.
6. Implications for Military and Civil Missions
With the increasing strategic reliance on space assets, failure to implement strong cryptographic protections invites espionage, sabotage, or denial-of-service from advanced adversaries. Civilian missions are especially exposed.
7. Recommendations
Short-Term:
- Adopt authenticated command headers (e.g., HMAC)
- Enforce uplink timing validation
- Tie command acceptance to dynamic keys or manifests
Long-Term:
- Implement CCSDS SDLS
- Integrate digital signature verification
- Deploy PKI-based spacecraft authentication systems
8. Conclusion
This paper demonstrates that passive sniffing—once viewed as harmless—is sufficient to compromise spacecraft protocol security when paired with long-term analysis and AI. Encryption and authentication are no longer optional. They are the minimum required for operational resilience in contested domains.
9. References
- CCSDS 350.5-G-2: Space Data Link Security
- NASA F’ (F Prime) GitHub Repository
- Aerospace Corporation: Threat-Based Architecture for Spacecraft
- arXiv: Cybersecurity Protections for Small Satellites (2505.09038)
- NIST SP 800-160 Vol 2: Cybersecurity for Systems Engineering
Tech Blog - Jorge Martinez 