Ethical Framework for Biometric Footwear Data

This document presents an ethical framework and data architecture for biometric footwear data, including 3D foot geometry, gait, posture, and centre-of-gravity measurements. The framework introduces a five-layer data classification model and a three-domain protection model that distinguishes personal data (governed by legal consent), craft knowledge (protected by cryptographic key ownership), and human heritage (preserved through irreversible feature transformation). A key contribution is the concept of Data Donation — a voluntary, irrevocable mechanism by which individuals contribute derived morphological features to the human knowledge commons, analogous to medical body donation. The framework also addresses the longitudinal and generational nature of footwear data, the misuse risk of gait data for surveillance, and the potential of footwear as a social infrastructure sensor for fall-risk mapping and barrier-free design. This work is published as a Defensive Publication to prevent monopolisation of these concepts and to provide an open reference model for the footwear industry, medicine, urban infrastructure, and academic research.