Towards Querying in Decentralized Environments with Privacy-Preserving Aggregation

The Web is a ubiquitous economic, educational, and collaborativespace, however, it also serves as a haven for personal information harvesting. Ex-isting decentralised Web-based ecosystems, such as Solid, aim to combat personaldata exploitation on the Web by enabling individuals to manage their data in thepersonal data store of their choice. Since personal data in these decentralisedecosystems are distributed across many sources, there is a need for techniques tosupport efficient privacy-preserving query execution over personal data stores.Towards this end, in this position paper we present a framework for efficient pri-vacy preserving federated querying, and highlight open research challenges andopportunities. The overarching goal being to provide a means to position futureresearch into privacy-preserving querying within decentralised environments.