# Blockchain and Self Sovereign Identity to Support Quality in the Food Supply Chain
## 2 Review
### SSI, Blockchain and IPFS  
Recently, many research papers investigated Blockchain's potential in combination with Internet of Things (IoT) [12; 13; 14; 15; 16; 17; 18] and/or with distributed systems such as IPFS [19; 20; 21; 22; 23; 24], for enhancing the integrity, auditing, information flows, and traceability of the supply chain, and contributing to scalability, security, and interoperability of the supply chain management systems. In this work, we propose a model that exploits Blockchain, IPFS, and the SSI concepts, thereby aiming at superior management and storage of the food/process certifications. The model is conceived in such a way to be easily integrated, in the near future, into complete and functioning SSI systems, in which each individual manages their entire identity, and all their claims, independently, without relying on a third party. Let us give some details about this new identity management system (ref. [[https://ecas.ec.europa.eu/cas/login](https://ecas.ec.europa.eu/cas/login)]([https://ecas.ec.europa.eu/cas/login](https://ecas.ec.europa.eu/cas/login)) (accessed on 15 November 2021)and [25]), that entails (may entail) numerous advantages in the supply chain management. Traditionally, the identification of people is performed through centralized systems, that uniquely identify and store people's data. Nowadays, thanks to digital transformation, data represents individuals, and the data owner no longer has control over their own data (Ref. [[https://www.lifewithalacrity.com/2016/04/the-path-to-self-soverereign-identity.html](https://www.lifewithalacrity.com/2016/04/the-path-to-self-soverereign-identity.html)]([https://www.lifewithalacrity.com/2016/04/the-path-to-self-soverereign-identity.html](https://www.lifewithalacrity.com/2016/04/the-path-to-self-soverereign-identity.html)) (accessed on 15 November 2021)). Whenever individuals use the network, by using social networks or carrying out economic transactions, third parties the so called \"service providers\" request them the \"user authentication\" to grant access to their services. In this way individuals leave on the network virtual footprints, that are their digital identities. The SSI models want to give back to individuals the possession and control of their data, and use digital wallets as a possible solution to collect all the individuals' data/attestations that each identity can boast. Thanks to blockchain and/or other distributed systems, these models could become a reality. Blockchain technology, and in general distributed systems, allow a new form of identity management. Precisely they allow the management of the so called decentralized identities (DIDs). A decentralized identity is a set of characteristics/claims that uniquely define natural persons, legal entities or things. Unlike conventional methods, a DID remains under the control of the individual. In this way, personal data are solely owned by the individual and are not registered with other parties. In addition, with encryption, the individual can demonstrate possession of the claims/attestations without sharing other information that is not strictly necessary, and thus ensure maximum respect for their privacy. The concepts of Zero-Knowledge Proof and Selective Disclosure, are focused both on the principle of data minimization and are used to reduce the exposure of individuals' personal information. So with SSI, the individual returns to having full control over their own identity, deciding if and which attributes/claims to make available to external parties. The European Blockchain Services Infrastructure (EBSI) (EBSI is a network of distributed nodes across Europe that will deliver cross-border public services.) works on the implementation of an European Self-Sovereign Identity framework (ESIF).