Secure distributed data and event processing at scale: where are we now?

The continuously increasing availability of cloud and edge data center resources is driving our evolution to a data-driven society. Meanwhile, however, the innate sharing of third-party data center resources by users continues to fuel strong security concerns around data and computations handled in and across such infrastructures. While many basic solutions to enforce security have been proposed over the years, both in terms of software mechanisms (cryptographic primitives) and hardware mechanisms (trusted execution environments), they all come with their respective pros and cons. In this talk I will report and reflect on almost a decade of experience of working on the problem of confidentiality-preserving data and event processing. I will cover challenges in terms of guarantees, performance, transparency, or portability and interoperability, discuss tradeoffs therein, solutions, and, finally, open challenges.