  Research challenges such as climate change and the search for habitable
planets increasingly use academic and commercial computing resources
distributed across different institutions and physical sites. Furthermore, such
analyses often require a level of automation that precludes direct human
interaction, and securing these workflows involves adherence to security
policies across institutions. In this paper, we present a decentralized
authorization and security framework that enables researchers to utilize
resources across different sites while allowing service providers to maintain
autonomy over their secrets and authorization policies. We describe this
framework as part of the Tapis platform, a web-based, hosted API used by
researchers from multiple institutions, and we measure the performance of
various authorization and security queries, including cross-site queries. We
conclude with two use case studies -- a project at the University of Hawaii to
study climate change and the NASA NEID telescope project that searches the
galaxy for exoplanets.
