Testing Prototypes for Exploring Federated Access to Sensitive Data via Trusted Research Environments

As sensitive data becomes increasingly central to research addressing societal challenges—particularly in health, social sciences, and public policy—there is an urgent need for infrastructure that enables secure, ethical, and streamlined access across institutional and national boundaries. Federated models for data access via Trusted Research Environments (TREs) offer a promising pathway, allowing data to remain under the control of its custodians while providing researchers with the tools and permissions needed to analyze data remotely under controlled conditions. Previous work by the International Data Access Network and the Social Science and Humanities Open Cloud projects has made great progress with pioneering bilateral data access pathways across international borders. But there remain significant challenges in this space. This paper presents work being conducted as part of the EOSC-ENTRUST project, which is establishing a European network of TREs and developing a federated framework for identity and access management (IAM) across European research infrastructures. It also draws on insights from the UK's SafePod Network, a national TRE initiative that provides secure physical locations for accessing sensitive data held by multiple providers. This work aims, through the testing of two prototypes, to explore how federated access to TREs can be enabled in practice, focusing on three key areas: (1) how successfully the tested prototypes facilitate the expansion of access to sensitive data across organizations and jurisdictions; (2) how successfully the prototypes enable new and developing TREs to make sensitive data available internationally; (3) identifying which barriers to adopting federated access the prototypes cannot solve; and (4) the user experience of researchers engaging with federated TREs. These will be evaluated through real-world use cases involving researchers seeking access to sensitive data under varying national governance frameworks. Prototype 1 is utilizing existing TRE infrastructure provided by SANE to provide remote desktop access to data held in a central TRE by researchers in three European countries. Prototype 2 is piloting the expansion of the SafePod Network model into European services by integrating federated SafePod access workflows, demonstrating how physical TREs can enhance flexibility and reduce administrative burden. Preliminary work shows that federated access to TREs is technically feasible and can significantly reduce time-to-access for approved researchers while maintaining high standards of data protection. Importantly, integration with existing models such as the SafePod Network highlights the potential to build hybrid federated infrastructures that combine physical and virtual access modalities, even in TREs with limited resources. However, challenges remain, particularly in aligning data access policies across jurisdictions, overcoming potential legislative barriers, and establishing scalable governance frameworks. The EOSC-ENTRUST project provides a foundation for addressing these challenges through the development of shared trust and policy frameworks and common standards for TREs, and this paper contributes practical insights for infrastructure providers and data custodians seeking to implement federated access models that respect both the rights of data subjects and the needs of researchers.