Security model
The Nebbos security model rests on five data tiers, four governance pillars, and six compliance frameworks. Each element below identifies the substrate-level mechanism through which the platform enforces the corresponding property.
Governance pillars
| # | Pillar | Enforcement mechanism |
|---|---|---|
| 01 | Attested human approval | Guest-tier reads clear on device-native biometric authentication. Host-tier writes require the Cradle physically present and produce a Cradle-signed delegation token. Architect-tier administrative operations require an additional enclave-signed approval token. The substrate verifies each signature before state changes. |
| 02 | Hash-chained audit | Every read, every write, and every tier decision is committed to an append-only, tamper-evident chain. External auditors verify the chain end-to-end from the exported bundle without vendor mediation. |
| 03 | Row-level isolation | Isolation is enforced at the database layer through native row-security policies. Queries against unauthorised scopes are refused before an answer is composed; the application layer cannot override the policy. |
| 04 | Continuous portability | The export path executes on every production deploy against scoped test tenants using the same code path a production export would take. Operators may execute an export at any time on their own schedule. |
Data tiers
The classifier assigns each tool call to a tier on the operator’s host prior to egress.
| Tier | Egress behaviour | Verification property |
|---|---|---|
| Sealed | No egress. Content is retained on the Cradle. | Absence of egress is verifiable in the audit chain. |
| Portable | Ciphertext-only server side. | Encryption key is held on the Cradle; server-side storage is opaque. |
| Redacted-to-cloud | Personally identifiable information is stripped on the host before egress. | External providers receive the shape of the request without identity information. |
| Attested-cloud | Enclave attestation required. | Provider responses are signed by the hardware that produced them; signatures land in the audit chain. |
| Air-gapped | No egress. Local weights, local model, local memory. | Deployment topology guarantees the absence of external network calls. |
Compliance posture
Compliance framework status is derived from the substrate and updated as certifications advance.
| Framework | Status | Detail |
|---|---|---|
| SOC 2 Type II | In progress | Controls implemented against the trust-services criteria; observation window and independent audit under way. Report not yet issued. |
| ISO 27001:2022 | Not yet held | Substrate technical controls implemented; information security management system in preparation. |
| EU AI Act · Annex IV | Pack in preparation | Technical documentation pack being assembled ahead of the 2027-08-02 obligation date. |
| HIPAA | Readiness | Substrate technical safeguards implemented; business associate agreement and administrative safeguards to be executed per deployment. |
| FERPA | Preventive | The Nebbos substrate does not currently process individual student records. Preventive controls are in place. |
| GDPR · CCPA | DPA available | Data processing addendum at nebbos.ai/legal/dpa. Data-subject rights implemented as first-class flows. |
See Compliance posture for the standalone framework reference and EU AI Act · Annex IV for the technical documentation pack structure.
Related references
- The audit chain — mechanism for pillar 02.
- Row-level isolation — mechanism for pillar 03.
- Portability & export — mechanism for pillar 04.