Abstract
The building industry is the most resource-intensive sector in industrialized countries. A shift towards a circular economy is vital to enhance resource efficiency and sustainability. Digital Product Passports (DPPs) are crucial in implementing circular practices by providing essential information. However, integrating DPP systems in the construction sector presents challenges, such as ensuring long-term system and data availability and determining the best method for accessing passport data. These issues will be addressed by designing, implementing, and evaluating a decentralized DPP system prototype with physical components for accessing passport data. The study compares Non-Fungible Tokens (NFTs), Physical Backed Tokens (PBTs), and Decentralized Identifiers (DIDs) for managing product identities and ownership. Additionally, it evaluates the use of QR codes and Hardware-Locked (HaLo) NFC chips for accessing passport data. The evaluation results indicate that while a fully decentralized DPP system design is feasible, implementing a smartphone app as the user interface component depends on centralized services. This raises concerns about the long-term availability of the system. No single digital identifier and data carrier combination excelled in all evaluation criteria. However, HaLo NFC chips were the most tamper-proof option, DID-based passports were more cost-effective, and QR codes offered faster processing.
Emmenegger, Pascal