# Blockchain and Self Sovereign Identity to Support Quality in the Food Supply Chain
## 1 Introduction  
Today, in an increasingly globalized world, companies connect ever more closely to their customers and partners around the world. Companies expand beyond national borders, aiming for continuous improvement and for increasing the trust and loyalty of their customers. They standardize their processes/procedures in such a way to be able to guarantee their customers to work methodically to achieve a specific result, so that the quality of the products marketed can always be guaranteed. In addition, they increasingly use certifications as direct or indirect guarantee tools in supply chains. For a company, having one or more certifications means being visibly placed on the market, being considered a reliable company, entering supply chains, and being able to export its products. Certifications help to simplify the production and to minimize the risks and consequences associated with them. Having a certification implies the implementation of strict controls in internal processes, the monitoring and verification of processing methods and compliance with hygiene requirements along the entire production chain. Behind a certification there is a Hazard Analysis and Critical Control Points (HACCP) system, procedures to define precise processing standards to be followed and a document management system that allows companies to manage, organize, share, and archive documents/files. Food/process certifications are not mandatory but they are increasingly requested by the market [1,2]. They give to companies a competitive advantage in the sector in which they operate. The certifications allow to assess compliance with the requirements on food safety, quality and legality and are essential for companies to be able to operate in international markets, where each country operates according to its own current legislation. Thus, given that for the food industry there are not standards valid around the world, it is very useful to own more than one certification. These certifications help to guarantee and increase trust and transparency to consumers, but also to suppliers, according to their target. There are certifications created to \"communicate\" with the final consumer, the so called _Business to Consumer certifications_ and certifications created to \"communicate\" with the Large-Scale Retail Trade, the so called _Business to Business certifications_. Food certifications are third-party verifications that products, processes, or systems in the food supply chain must meet to satisfy food standards [3]. By means of these certifications, a third independent party, which can be for example a certification body, a test laboratory, a certification center or a calibration center, certifies with a sufficient level of confidence that a particular product, service, or process complies with a given standard or technical regulation. This is a typical third-part model, in which if an/a actor/participant along the supply chain wishes to own a certification has to start a request process to obtain the desired certification signed by a trusted authority. On the other side if a participant along the supply chain wishes to verify the validity of a given certification, to ascertain that the certification is issued by a trusted body, he/she has to start a verification process that could take hours or days since food supply chains are hardly digitalized and food documentation are typically stored on paper or private databases [4; 5]. In light of these considerations, our research question is that of studying and analyzing whether the SSI concepts applied within a supply chain ensure eligibility, transparency, and traceability of the certifications along the chain. This work deals with the storage and the retrieval of food supply chain certifications, and presents a system in which the validity of all certifications owned by the several participants along the supply chain is verified against a decentralized and trusted registry of information.