The increasing centralization of the Web raises serious concerns regarding privacy, security, and user autonomy. In response, there has been a renewed interest in the development of secure personal information management systems and a movement towards decentralization. Decentralized personal online data stores (pods) represent a revolutionary example within this movement, built on the W3C’s existing guidelines – an approach exemplified by initiatives such as Solid (https://solidproject.org). In the Solid paradigm, individuals store their personal data in pods and have absolute discretion when choosing to grant access to different users and applications. A barrier to the adoption of the pod approach is the predominant reliance on centralized indexes for search functionality in current Web and Web-based systems. This paper introduces the ESPRESSO framework, which is designed to facilitate this new paradigm of large-scale searches within personal data stores while respecting the individual pod owners’ data access governance. The current ESPRESSO prototype integrates access control within pod indexes to enhance distributed keyword-based search. ESPRESSO’s unique contribution not only enhances search capabilities on the decentralized Web but also paves the way for future explorations in decentralized search technologies.
