07 — Implementation and Roadmap

1. What ships in this bundle

Reference crate v2/crates/wifi-densepose-privshield (VEIL): a deterministic, dependency-free, WASM-ready pure-compute leaf implementing the full attacker-vs-protector experiment, the four compliant controls, the throughput model, the compliance audit, the optimize hyper-optimizer, and a byte-stable proof. 35 tests + doctest pass; builds for wasm32-unknown-unknown; clippy-clean.
This research bundle (docs/research/privacy-shield/).
ADR-288 — the formal decision record.
npm metaharness harness/wifi-densepose-privshield/ (ADR-289) — a per-crate contributor harness (architect/implementer/reviewer/test-writer, router, flywheel) with a dependency-free guidance surface that serves this bundle's capability map. npx wifi-densepose-privshield-harness guidance --topic optimization.

The crate is intentionally a leaf with no internal RuView dependencies (mirrors wifi-densepose-aether), so it can be reasoned about, fuzzed, and ported independently, and so it can never accidentally acquire a path to a radio.

2. Reuse map (how VEIL composes with existing RuView)

Existing subsystem	Relationship
BFLD (ADR-118/120/121, `wifi-densepose-bfld`)	Detection layer. Its `identity_risk_score` is the natural trigger for VEIL's `SensingDetector` — detect leakage, then shield
Privacy control plane (ADR-141)	VEIL protection steps emit `ComplianceReport`s that fit the runtime-attestation model (which mode, which actions, which fields)
Active sensing / governed actuation (ADR-280)	VEIL is a defensive `SensingAction`: a governed, privacy-ceiling-bounded emission-shaping action the control plane can schedule
Givens/beamforming primitives	VEIL reuses the report's native Givens-rotation structure rather than inventing a new transform
Deterministic proof discipline (`nvsim`, `archive/v1/verify.py`)	VEIL's `proof` module follows the same pinned-witness pattern

3. Phased rollout

Phase	Deliverable	Evidence class
P1 — reference model (this PR)	Crate + experiment + docs + ADR	SYNTHETIC (cargo test)
P2 — sensitivity study	Sweep N, noise, resolution, mixing; add a learned attacker to confirm signal-level collapse	SYNTHETIC
P3 — BFLD integration	Wire `identity_risk` → `SensingDetector` → shield engage; emit attestation	SYNTHETIC + integration tests
P4 — firmware feedback shaping	Implement keyed fine-subspace rotation + cadence randomization in the beamforming-feedback / spatial-mapping path — see §3.1 for the (non-trivial) platform reality	build + hardware
P5 — two-node hardware measurement	Attacker (Wi-BFI capture) vs. VEIL protector on real silicon; iperf throughput; captured log	MEASURED (with witness)
P6 — deployment profiles	Per-segment profiles (SCIF, boardroom, ward) with regulatory review	operational

No defense claim graduates from SYNTHETIC to MEASURED without a captured boot/runtime log (CLAUDE.md hardware rule).

3.1 Does this need custom WiFi firmware? (yes — and ESP32 is the wrong chip for the protector)

VEIL shapes the compressed beamforming report (the Givens φ/ψ angles) or the LTF spatial mapping as it is transmitted — machinery that lives below the driver, inside the chip's PHY/MAC firmware. It is not reachable from user space, so a real deployment is a firmware/driver change, not an app.

ESP32 — not viable as the protector. Its WiFi lower layers are a closed Espressif blob. ESP-IDF exposes CSI read (esp_wifi_set_csi) — which is why firmware/esp32-csi-node/ makes a great attacker/sensor node — but it does not let you rewrite how the chip builds/sends beamforming feedback. ESP32 is the attacker in a testbed, not the shield.
Realistic protector platforms: openwifi (open 802.11 on SDR/FPGA — full PHY/MAC control incl. the AP-side compensation; the honest end-to-end route; Verilog + a C driver); Nexmon (C firmware patches for Broadcom/Cypress, e.g. RPi BCM43455 — the commodity path, and the same framework the BFI attack tools already use); open drivers (ath9k/mt76) for partial control; or vendor firmware for a production feature.
Two firmware variants: the keyed-reversible version (VEIL's ~98% throughput) needs changes on both ends plus key agreement (cf. the LeakyBeam AP-side Q_obf is client-transparent — only the AP changes — which is a deployment advantage worth adopting, §09 backlog item 3); the emitter-only DP dither version needs only the reporting device but pays the full throughput cost.

The current crate is deliberately a std-only, no-radio leaf and implements none of this; P4 is where it meets silicon.

4. Open problems (tracked honestly)

Real-hardware separability. Comm and identity information are only approximately separable on real radios; the true throughput cost of full identity hiding may exceed the model's ~2%. P2/P5 must bound it.
Within-session motion leakage. A fixed per-session rotation does not obfuscate coarse motion within one capture window. Needs stronger cadence randomization or amplitude shaping; currently a stated non-goal for the re-ID metric.
Active adversary (A2). An attacker that transmits its own soundings is only partially addressed by cadence control; a MAC-layer non-response policy is needed.
Key management. The per-session rotation key must be derived from the negotiated link secret; VEIL's PRNG is explicitly not cryptographic and must not be used for real key material.
Regulatory review per jurisdiction. The energy-conservation argument is portable, but power/mask/timing limits and any transmit-nulling profile need local review before field use.

5. Validation commands

# Reference experiment + all unit/proof/doc tests
cargo test -p wifi-densepose-privshield --no-default-features

# WASM portability (leaf builds with no radio path)
cargo build -p wifi-densepose-privshield --target wasm32-unknown-unknown

# Lints
cargo clippy -p wifi-densepose-privshield --all-targets

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