Blockchain-based Notarization for Digital Product Passports

Digital Product Passports (DPP) act like a digital identity for products that provide a lot of informa- tion on their lifecycle and supply chain. DPP are gaining popularity because they allow consumers to access information directly at the point of sale, often scanning a QR code placed on the label of the product. This transparency may lead to a transition to a green economy because it allows consumers to make informed purchasing based on environmental metrics. Building upon an existing DPP software tailored for the fashion industry, this thesis focuses on data trustworthiness and integrity; the main objective is to implement a notarization system that ensures non-repudiation, so the companies cannot alter the data or denying the fact that they reported them. It is important to note that this thesis does not address in any way the truthfulness of the data, but rather the immutability of the information once recorded. To achieve this, this thesis proposes a decentralized approach using blockchain technology. By eliminating the problem of a single point of failure, this research proposes a robust mechanism to ensure trust in the transparency of the DPP data. This research focuses on the usability of the system for small and medium companies that often lack the economic, infrastructural, and technical resources to implement proprietary solutions. To mitigate these barriers, the concept of an aggregation center is introduced.