In our increasingly digitized world, the value of data is clear and proved, and many solutions and businesses have been developed to harness it. In particular, personal data (such as health-related data) is highly valuable, but it is also sensitive and could harm the owners if misused.
In this context, data marketplaces could enhance the circulation of data and enable new businesses and solutions. However, in the case of personal data, marketplaces would necessarily have to comply with existing regulations, and they would also need to make users privacy protection a priority. In particular, privacy protection has been only partially accomplished by existing datamarkets, as they themselves can gather information about the individuals connected with the datasets they handle.
In this thesis is presented an architecture proposal for KRAKEN, a new datamarket that provides privacy guarantees at every step in the data exchange and analytics pipeline. This is accomplished through the use of multi-party computation, blockchain and self-sovereign identity technologies. In addition to that, the thesis presents also a privacy analysis of the entire system.
The analysis indicated that KRAKEN is safe from possible data disclosures to the buyers. On the other hand, some potential threats regarding the disclosure of data to the datamarket itself were identified, although posing a low-priority risk, given their rare chance of occurrence. Moreover the author of this thesis elaborated remarks on the decentralisation of the architecture and possible improvements to increase the security. These improvements are accompanied by the solutions identified in the paper that proposes the adoption of a trust measure for the MPC nodes.
The work on the paper and the thesis contributed to the personal growth of the author, specifically improving his knowledge of cryptography by learning new schemes such as group signatures, zero knowledge proof of knowledge and multi-party computation. He improved his skills in writing academic papers and in working in a team of researchers leading a research area
