Aniket Kate, Differential Guarantees for Cryptographic Systems

Differential privacy aims at learning information about the population as a whole, while protecting the privacy of each individual. With its quantifiable privacy and utility guarantees, differential privacy is becoming standard in the field of privacy-preserving data analysis. On the other hand, most cryptographic systems for their privacy properties rely on a stronger notion of indistinguishability, where an adversary should not be able to (non-negligibly) distinguish between two scenarios. Nevertheless, there exists some cryptographic system scenarios for which the notion of indistinguishability is known to be impossible to achieve. It is natural to ask if one can define differential privacy-motivated privacy notions to accurately quantify the privacy loss in those scenarios. In this talk, we will study two such scenarios.Our first scenario will consider (non-)uniform randomness employed in cryptographic primitives. It is well-known that indistinguishability-based definitions of cryptographic primitives are impossible to realize in systems where parties only have access to non-extractable sources of randomness. I will demonstrate that it is, nevertheless, possible to quantify this secrecy (or privacy) loss due to some non-extractable sources (such as the Santha-Vazirani sources) using a generalization of indistinguishability inspired by differential privacy.Our second scenario will capture privacy properties of anonymous communication networks (e.g., Tor). In particular, I will present our AnoA framework that relies on a novel relaxation of differential privacy to enables a unified quantitative analysis of properties such as sender anonymity, sender unlinkability, and relationship anonymity. About the speaker: Prof. Aniket Kate is an assistant Professor in the the computer science department at Purdue university. Before joining Purdue in 2015, Prof. Kate was a junior faculty member and an independent research group leader at Saarland University in Germany, where he was heading the Cryptographic Systems Research Group. He was a postdoctoral researcher at Max Planck Institute for Software Systems (MPI-SWS), Germany for 2010 until 2012, and he received his PhD from the University of Waterloo, Canada in 2010.Prof. Kate designs, implements, and analyzes transparency and privacy enhancing technologies. His research integrates applied cryptography and distributed systems.