Digital Signing of Physical Items Protocol (DSPIP)

This document specifies the Digital Signing of Physical Items Protocol (DSPIP), a cryptographic protocol for authenticating physical items using digitally signed QR codes. This specification focuses on the SHIP type for shipping and logistics applications, providing cryptographic authentication of packages with chain of custody tracking. The protocol introduces privacy-preserving delivery mechanisms including encrypted recipient information, last mile provider selection, physical anti-cloning protections through split-key labels, and scalable revocation and delivery confirmation systems. DSPIP uses DNS-based public key distribution similar to DKIM and supports optional blockchain integration for immutable record keeping. While this specification focuses on shipping applications, the protocol includes a type field to enable future expansion to other use cases.