Paul Rösler, Horst Görtz Institute for IT-Security, Ruhr University Bochum
From 12.00 until 13.30
At CNB/F/110 (Lunch) + CAB/F/100.9 (Seminar), ETH Zurich
Universitätstrasse 6, 8092 Zurich
Abstract:
Modern messaging protocols are highly complex as they are composed of multiple different cryptographic primitives. In order to understand the underlying security requirements, security guarantees, and mechanisms, this talk disassembles messaging into its components. The main focus will be ratcheting as a modern building block that provides security even if secrets from the communicating devices are obtained by an attacker. Recent research in the area of ratcheting produced multiple different security definitions and constructions with barely comparable security guarantees and efficiency properties. The talk will be concluded with a short overview and systematization of this line of research and an intuition why some security notions imply the use of inefficient cryptographic building blocks for instantiations.