## 5 Assessment
### Security and Privacy Assessment  
As described in Section 4, the REFINERY Platform fulfills all functional data administration tasks that arise in the context of data refinement, namely data acquisition, data preparation, data management, and data provisioning. In addition, data security and data privacy precautions are intrinsically integrated into each of these process steps, as required to ensure a reliable handling of the valuable commodity 'data'. Since these precautions are coordinated and seamlessly intertwine due to the holistic approach, end-to-end data protection is guaranteed. Since the application of these precautions is coordinated and all individual measures are closely intertwined, end-to-end data protection is achieved. In the following, we assess whether the protection goals (see Section 3.2) and privacy requirements (see Section 3.3) in this context are addressed in the REFINERY Platform. The confidentiality of the data is ensured on the side of the data producer since they are stored solely in encrypted form in our secure data store on the edge devices. That is, they are protected against illegal access right after they have been captured. The data producer defines via the privacy requirements which of these data are forwarded by the PMP to the REFINERY Platform. This further promotes confidentiality, since only a portion of the data leaves the data producer's sphere of influence and can thus be leaked in the first place. For transmission and during data refinement, the data are signed. In general, a digital signature does not protect against unwanted access, since the data are encrypted with the private key of the data owner and thus anyone who has the public key can verify the signature, i.e., decrypt the data. However, in our case, only the REFINERY Platform has the necessary public keys. That is, the digital signature automatically guarantees confidentiality during transmission and storage in the REFINERY Platform as well. Since for the data preparation only samples that meet the privacy requirements can be accessed by the data standards, confidentiality is also maintained in this process step. Even the data processing rules are specified without granting third parties deep insights into the data. External third parties (e.g., data consumers) can only access the data products via restricted interfaces, namely the Data Delivery Zone. Here, an access policy set by the data producers regulates who may access which data products and for what purpose. Two main techniques are used to verify the integrity of the data: On the one hand, the REFINERY Platform can use the digital attribute-based signature to check how the data were captured, as it contains, e.g., information about the sensor used for this purpose and its accuracy. Furthermore, the privacy requirements are included in the signature as well. That is, the REFINERY Platform knows which distortions have been made to the data on the part of the data producer and which constraints have to be respected during data refinement. This transparency makes it possible to determine whether the quality of the raw data meets the quality requirements of a data consumer. Furthermore, manipulations by any third parties (e.g., during transmission) can be detected due to the signatures. While this does not prevent such manipulations, it can be ensured that no corrupted data can make its way into the data store of the REFINERY Platform. On the other hand, the integrity of the raw data after they have been transmitted is ensured by blockchain technologies. By means of the information stored in the blockchain (either the data items themselves or their digital fingerprints), it is possible to verify that the data in the Raw Data Zone have not been tampered with. Since the ontology with the processing rules provides a complete lineage of each data product, this also ensures the integrity of these products. If there is any doubt about the integrity of a data product, the raw data can first be verified and then the data product can be reproduced using the ontology.