Providentia Talk by Boel Nelson: Towards Provable Transport Layer Privacy

Abstract:

Confidentiality of metadata is a challenging privacy problem. Most systems today ensure confidentiality of data using encryption, but they do not address confidentiality of metadata. For example, encrypted data still leaks metadata such as when a message is sent, how long it is, and to whom it is addressed. While metadata privacy is a known problem, existing solutions are far from perfect: they are either resource exhaustive which affects performance, or they guarantee only weak notions of privacy.

In this talk I present the problem of transport layer privacy, and outline a novel formalization of the problem using information flow control techniques that introduces a new trade-off between performance and privacy for anonymous communication. To exemplify I present a provably private protocol for instant messaging which we call Deniable Instant Messaging, DenIM for short.

Joint work in progress with E. Pagnin and A. Askarov.

Bio:

Boel Nelson is a Marie Skłodowska-Curie postdoctoral fellow in the Logic and Semantics group at Aarhus University. She currently leads the MSCA funded project Provable Privacy for Metadata (ProPriM, https://cordis.europa.eu/project/id/101064140). Boel’s research interests include data privacy, detection and mitigation of side-channels, and privacy enhancing technologies.

Prior to joining Aarhus University, Boel worked as a postdoc focusing on differential privacy in the Algorithms and Complexity section at University of Copenhagen, and was a member of BARC. Before, she worked as a postdoc in the Logic and Semantics group at Aarhus University, where she conducted research on anonymous communication. Boel earned her PhD on the topic of differential privacy from Chalmers University of Technology in 2021.