QIF-T0096

Multi-modal biometric fusion attack (cross-sensor identity correlation for persistent tracking)

By fusing biometric signatures from multiple consumer sensors — ear canal acoustics (T0079), gait pattern (T0088), BLE RF fingerprint (T0091), PPG waveform (T0093), and eye tracking (T0085 if VR/AR) — an attacker creates a multi-modal biometric profile that is virtually impossible to evade. Each individual biometric can potentially be disrupted (change earbuds, alter gait, disable Bluetooth), but the fusion of 3+ biometric channels provides robust identification even if individual channels are degraded. The fusion operates at the feature level (concatenated feature vectors) or decision level (majority voting across classifiers). This technique weaponizes the ubiquity of consumer sensors: the average person carries 10+ sensors across phone, watch, and earbuds. The combination creates a biometric surveillance net that no single privacy measure can defeat.