Protocol Reference

Camera captures motion at 30fps. MediaPipe Pose extracts 33 landmarks.

SST mapper converts to standardized 18-point topology (§2.2).

Feature Pipeline (§3): Preprocessing → Temporal → Kinematic → Entropy → Hash.

Output: Motion Vector — a fixed-size geometric signature, not raw video.

The raw signal never leaves the device. Only the hashed vector is transmitted.

4-dimensional Presence Entropy Score (PES §3.5):

μTiming Variance — micro-second frame timing irregularities (biological).

Noise Residual — signal-to-noise ratio from low-pass prediction error.

Frequency Entropy — Shannon entropy over DFT power spectrum.

Biological Perturbation — cross-joint jerk correlation (6 joint pairs).

Combined via weighted sum: PES = 0.20·μT + 0.25·ε + 0.20·Hf + 0.35·Bio.

False Accept Rate (FAR): empirically < 5% for AI-generated motion (PES threshold 0.65).

False Reject Rate (FRR): < 15% for real humans in normal standing conditions.

Entropy Gap Theorem (§10) proves: Pr[AI PES ≥ 0.65] → 0.

Note: These are protocol-level metrics, not conventional FAR/FRR. MyShape verifies presence, not identity.

Minimum: 640×480 camera, 20fps, any modern browser (Firefox recommended).

Recommended: 1280×720, 30fps, dedicated webcam.

Processing: all on-device. No GPU required. No cloud dependency.

Latency: < 100ms for feature extraction. < 10ms for proof verification.

Proof size: < 512 bytes (ZK-Presence composite).

Platform support: Web (TypeScript SDK). iOS/Android/Unity/Unreal (planned).

8 attack signatures detected across 4 PES dimensions (§5):

Generative AI — frequency entropy collapse + missing jerk correlation.

Replay — uniform inter-frame timing + stale hash.

Imitation — cannot replicate unconscious micro-motion patterns.

Mocap — over-clean data lacks biological noise.

Sensor spoofing — inter-frame consistency checks + frequency monitoring.

Adversarial pose injection — MV normalization removes perturbations.

Statistical forgery — cannot satisfy all 4 dimensions simultaneously.

Digital twin — lacks original neural noise source.

Defense-in-depth: 5-layer architecture with independent security boundaries.