Sovereign AI at the Front Door of Care: A Physically Unidirectional Architecture for Secure Clinical Intelligence
Organizations: 6Hats AI Labs Inc. · University of California, Berkeley
Abstract
We present a Sovereign AI architecture for clinical triage in which all inference is performed on-device and inbound data is delivered via a physically unidirectional channel, implemented using receive-only broadcast infrastructure or certified hardware data diodes, with no return path to any external network. This design removes the network-mediated attack surface by construction, rather than attempting to secure it through software controls. The system performs conversational symptom intake, integrates device-captured vitals, and produces structured, triage-aligned clinical records at the point of care. We formalize the security properties of receiver-side unidirectionality and show that the architecture is transport-agnostic across broadcast and diode-enforced deployments. We further analyze threat models, enforcement mechanisms, and deployment configurations, demonstrating how physical one-way data flow enables high-assurance operation in both resource-constrained and high-risk environments. This work positions physically unidirectional channels as a foundational primitive for sovereign, on-device clinical intelligence at the front door of care.
Figures & tables
| Configuration | Enforcement | Def. 4.1 |
|---|---|---|
| Firewall rule | Software | No |
| Managed IP, outbound disabled | Kernel policy | Conditional |
| 5G Broadcast (NR MBS) | Config, bidir platform | Conditional |
| Software data diode | Software/firmware | Conditional |
| Hardware data diode | Hardware | Yes |
| Satellite (DVB-S2/S2X) | Hardware + spectrum | Yes |
| Attack Class | Connected Terminal | Sovereign AI Arch. |
|---|---|---|
| Remote code execution | Possible via NIC | Eliminated ( ) |
| Network scanning | Terminal visible | Eliminated ( ) |
| Lateral movement | Possible via | Eliminated ( ) |
| Worm propagation | Possible | Eliminated (Thm. 6.4 ) |
| Botnet enrollment | Possible | Eliminated (Cor. 6.5 ) |
| Man-in-the-middle | Possible | Eliminated (no path) |
| Attack Class | Mitigation |
|---|---|
| Optical capture | Time-bounded , physical security |
| Optical output capture | Physical security, display orientation |
| USB device injection | VID/PID/class whitelist + attestation |
| Chassis intrusion | Tamper detection, volatile wipe |
| RF injection near antenna | Physical security perimeter |
| Broadcast injection | Signature verification (Assumption 2.3 ) |
Appendix figures & tables4 assets
Supplementary material from the paper’s appendix.
Appendix
| Property | Value |
|---|---|
| Unidirectionality enforcement | Hardware (transmit circuitry absent) |
| Definition 4.1 satisfied | Yes—unconditionally |
| Typical downlink throughput | 20–100 Mbps (DVB-S2X ACM) |
| Coverage footprint | Continental (GEO) or global (LEO) |
| Terminal count scalability | Unlimited—broadcast is one-to-many |
| Network infrastructure at receiver | None—power and antenna feed only |
| Property | Value |
|---|---|
| Unidirectionality enforcement | Hardware (certified data diode) |
| Definition 4.1 satisfied | Yes—unconditionally |
| Typical throughput | Up to 10 Gbps (device-dependent) |
| Coverage | Point-to-point or hub-and-spoke |
| Network infrastructure at receiver | Diode receive port only—no bidirectional NIC |
| Return channel for fleet management | None toward source network |
| Property | Value |
|---|---|
| Unidirectionality enforcement | Kernel policy + perimeter firewall |
| Definition 4.1 satisfied | Conditional—absent under correct operation |
| Typical throughput | Standard Ethernet/IP rates |
| Coverage | Institutional LAN/WAN |
| Network infrastructure at receiver | Standard NIC—full hardware retained |
| Return channel if policy fails | Possible |
| Property | Config 1: Broadcast | Config 2: Diode | Config 3: Managed IP |
|---|---|---|---|
| Def. 4.1 satisfied | Yes (unconditional) | Yes (unconditional) | Conditional |
| Unidirectionality basis | No TX circuitry | Certified HW diode | Kernel + firewall policy |
| SW subversion possible | No | No (at diode boundary) | Yes (if policy fails) |
| Coverage model | Broadcast 1:many | Point-to-point | IP 1:1 or 1:many |
| Return channel possible | No | No | Yes if misconfigured |
| Fleet scalability | Unlimited | One port per terminal | Standard IP scaling |
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