# AEGIS — Continuous Security Validation & Architecture Review

- **Document ID:** ARCH-55
- **Phase:** E.4 — Readiness & Long-View
- **Status:** Draft for review (post four-reviewer discipline)
- **Version:** 0.1
- **Date:** 2026-07-10
- **Owner:** Chief Security Architect

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## 1. Purpose

Codify the ongoing engineering loop that keeps AEGIS's architecture live. Combines Continuous Adversarial Validation (ARCH-50) with the periodic Continuous Architecture Review (mandate #49). Security is a continuous cycle (mandate #4), never a final phase.

## 2. Continuous Security Validation (running)

- CAV Runner (ARCH-50) + Threat Simulation (ARCH-39) + Chaos (ARCH-48) + Blue-Team tuning (ARCH-46).
- Weekly summary published.
- Distributional drift alarms.

## 3. Continuous Architecture Review (periodic)

Cadence (mandate #49):

- **Major releases** — architecture snapshot review; deltas vs. prior release.
- **Annual** — full ARCH-* corpus health check; principle drift; open ADR pipeline; Debt trend.
- **Major threat landscape change** — trigger event forces ARCH-03 diff + review.
- **Major platform change** — new subsystem, new provider, new deployment topology.

## 4. Review Outputs

- Refreshed Verification Matrix rows.
- Debt Register updates.
- Retired assumptions; new hypotheses.
- ADR pipeline priorities.
- Architecture Health Metrics review (ARCH-44).

## 5. Trigger Handling

- Every trigger event opens a Review Ticket with SLO.
- Auditor visibility on trigger backlog.
- Review Ticket closure produces a signed review artifact.

## 6. Living Cycle (mandate #4)

The eight-step cycle diagrammed: Architecture → Implementation → Verification → Deployment → Operation → Monitoring → Learning → Architecture Improvement → (back to Architecture). Every review contributes to Architecture Improvement.

## 7. Assumption (hypothesis)

- **H-1.** *Combined running validation + periodic review keeps architecture aligned with reality within one review cycle.*
   - Evidence: initial baselines.
   - Validation: measure architecture drift + related incidents.
   - Confidence: Medium.
   - Expiration: annually.
   - Review Date: 12 months.

## 8. Trust Score Contribution

Fed into `Verification` + `Threat Activity` dimensions.

## 9. Independent Architecture Review

- **F-1.** *Cadence sustainability.* Owned + budgeted.
- **F-2.** *Trigger noise vs. signal.* Threshold-based triggers; auditor review.

## 10. Adversarial Architect Review

- **A-1.** *Insider skips a review cycle.* Cadence enforced; overdue review = SEV-3.
- **A-2.** *Trigger events suppressed.* Consistency checker verifies trigger-to-review link.

## 11. Operational Reliability Review

- **O-1.** Council meetings sustainable.
- **O-2.** Review artifacts durable + searchable.

## 12. Self-Critique

- **S-1.** *"Annual" is a long window.* Complementary to CAV weekly.
- **S-2.** *Reviews may over-focus on recent memory.* External advisor + historical baseline.

## 13. First-Target Analysis and Redesign

**Target:** review completion becoming performative. Response: outcome-based review — each review must produce concrete deliverables (Verification Matrix updates, Debt Register touches, ADR pipeline changes). Empty reviews are a metric signal.

## 14. Future Risks / Known Limitations / Out-of-Scope / Retirement

- **Future Risks.** Cadence proliferation as platform grows.
- **Known Limitations.** Periodic review is snapshot-in-time.
- **Out-of-Scope.** Emergency architecture changes (handled by ADR + IR).
- **Retirement Conditions.** Never.

## 15. Decisions

### D-55-1. Combined CSV (running) + CAR (periodic) with outcome-required reviews

- **Reason.** Mandates #4 + #49.

## 16. Change Log

- **0.1 (2026-07-10)** — Initial draft.