The Passive Sensor Engine
47+ Behavioural Vectors.
The SDK's biometric collector runs a 32-channel passive sensor engine with zero extra UX friction — 47+ distinct named metrics in total, grouped below.
// Touch Primitives
Pressure Dynamics (avg + variance)
Finger Contact Ellipse (major/minor)
Swipe Velocity Profile
Gesture Curvature Entropy
// Micro-Jitter & Hesitation
Micro-Jitter Score (Bézier-path deviation)
Touch Ellipse Evolution
Hesitation Intervals (down → first move)
Tap Interval / Touch Variance
// Phone Posture & IMU
Holding Pitch & Roll (accelerometer)
Gyro Yaw / Accel RMS
Micro-Movement / Jerk Index
Grip Variance & Tremor Zero-Crossing Rate
// Keystroke Dynamics
Key Dwell / Flight Time
Typing Speed & Error Rate
Backspace Frequency & Autocorrect Rate
// Session & Environment
Screen Dwell Time & Anomaly Z-Score
Back-Navigation Count / Hesitation Gaps
Ambient Light & Battery Drain Rate
// Coercion-Specific (Digital Arrest / Romance Scam)
Tremor RMS — 8–12Hz fear-tremor band
Grip Rigidity Score
Pressure Ramp Score (grip-tightening correlation)
Fused by the Behavioural Integrity Engine into a single deviation score against a calibrated per-device baseline — not compared against a generic population average.
See It In Action
Watch the Attack Fail.
TRANSFER STARTED
TYPING LOOKS NORMAL
SCREEN IS CHECKED
REMOTE CONTROL FOUND
SESSION STOPPED
Ready to begin.
The Verdict.
"BioCatch tells you how they typed. NonaShield proves what they were seeing when they typed"[cite: 374].
Engineered Prevention
Deterministic Trust vs Probabilistic Security [cite: 375]