The Glass Curb: A Zero-Trust Architecture for Data Minimization in Retail Curbside Fulfillment

The rapid growth of Buy Online, Pick Up In-Store (BOPIS) and curbside fulfillment has outpaced the development of privacy standards for the physical handoff. This audit documents a specific vulnerability in standard retail mobile telematics: frontline employee devices routinely display unmasked Personally Identifiable Information—full legal names, vehicle descriptors, and EBT/financial status—before the customer has arrived. This over-provisioning of data violates the Principle of Least Privilege (PoLP), creates direct liability under the California Privacy Rights Act (CPRA), and opens vectors for social engineering, targeted stalking, and operational bias. This paper proposes the Zero-Trust Curbside Protocol, an architectural standard built on Just-in-Time (JIT) Location-Based Decryption. Consumer data stays encrypted and anonymized through session-based aliasing until two physical conditions are satisfied: validated employee presence at a designated geospatial node (Parking Bay scan) and client-side verification through a rotating One-Time PIN (OTP). This "Blind Handoff" mechanism cuts liability exposure and eliminates Ghost Delivery fraud without slowing fulfillment.