Data trustees serve as intermediaries that facilitate secure data sharing between independent parties. This paper offers a technical perspective on Data trustees, guided by privacy-by-design principles. We introduce PrivTru, an instantiation of a data trustee that provably achieves optimal privacy properties. Therefore, PrivTru calculates the minimal amount of information the data trustee needs to request from data sources to respond to a given query. Our analysis shows that PrivTru minimizes information leakage to the data trustee, regardless of the trustee's prior knowledge, while preserving the utility of the data.
@article{arxiv.2506.06124,
title = {PrivTru: A Privacy-by-Design Data Trustee Minimizing Information Leakage},
author = {Lukas Gehring and Florian Tschorsch},
journal= {arXiv preprint arXiv:2506.06124},
year = {2025}
}