## 5 Assessment
### Feature Discussion
\begin{table}
\begin{tabular}{l l l} \hline \hline
**Data Administration Task** & **Key Contributions to Data Security** & **Key Contributions to Data Privacy** \\ \hline \multirow{3}{*}{_Data Acquisition_} & On edge devices, data are fully encrypted. The data producers stipulate which data are transmitted. Digital signatures secure the transmission. & Data subjects specify privacy requirements that are applied by means of PET (e.g., privacy filters) on edge devices and in the REFINERY Platform. \\ \hline \multirow{3}{*}{_Data Preparation_} & The applied sample-based data preparation ensures that no unauthorized insights into the data can be gained. & Data subjects specify a privacy threshold that is respected when selecting the data samples for the data stewards. \\ \hline \multirow{3}{*}{_Data Management_} & Blockchain technologies ensure the integrity of the transmitted data via digital fingerprints. & Additional PET can be applied to a data product before it is distributed. \\ \hline \multirow{3}{*}{_Data Provisioning_} & Our access control model enables to define who is allowed to access which data. Data access may be subject to additional privacy restrictions. & Since our model maps retrieved data to revealed knowledge patterns, this approach allows for truly informed consent. \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Summary of the Key Contributions of the REFINERY Platform with Regard to Data Security and Data Privacy. information is turned into a data product. Data consumers can add further processing rules or adapt existing ones if no available data product meets their needs. Our PET include specialized privacy filters that are tailored to certain types of data. These filters can be used to conceal specific information contents without rendering the data unusable for an intended purpose. HDFS is used for the implementation of the Raw Data Zone. With this file system, it is possible to add further nodes at any time in order to increase capacity. Due to decreasing prices for hard disk space, it is therefore possible to store all available raw data, even if their economic value is initially uncertain (Characteristic VII). We address the fact that data can be manipulated indiscriminately (Characteristic VIII) by means of our data integrity measures. Blockchain technologies are used to verify that the stored raw data, which represent the ground truth for all data products, have not been manipulated. Digital signatures ensure that they have not been secretly falsified by third parties during transmission. These signatures also describe which PET have already been applied to the data in the user-controlled area. Therefore, it is not only possible to prevent all illegitimate data manipulations but also to communicate these justified distortions by the data producers (in accordance with their privacy requirements) to the data consumers in a transparent manner. In addition, the selection of PET is matched to the intended use case, i.e., their impact on the data attributes relevant for the data consumer is as low as possible. In addition to the PET, our purposed-based access policy model ensures that special restrictions regarding the handling of certain data can be complied with (Characteristic IX). This access policy is used in the Data Delivery Zone and maps for which purpose which data consumer has access to which data products. Access can be further restricted by means of activation contexts that can be attached to each access policy rule. All data products are described by means of our machine-processable ontology. Recommender systems can therefore use the ontology to point data consumers to similar data products that might also be relevant to them. Data consumers can also extend the ontology to design customized data products for their particular use cases. This forms the foundation for a data marketplace. That is, our REFINERY Platform provides the required concepts and infrastructures to trade the commodity 'data' (Characteristic X).