Organizer: Patrick Harasser
Secure channels allow two or more users to communicate in a confidential and authentic manner over an unprotected network. The general understanding seems to be that providing authenticated encryption (AE) security for every point-to-point link yields a secure channel. In particular, cryptographic analyses of deployed protocols including TLS and SSH treat these protocols as AE primitives. However, while AE is restricted to unidirectional communication (from a sender to a receiver), TLS and SSH are meant to offer protection in the two directions. Going further, in group communication multiple directions need to be protected simultaneously.
In this talk I will present recent results on channel security, introducing richer models that account for the distributed nature of bidirectional and group communication. I will highlight that, particularly in the multi-directional case, security notions need to capture aspects related to the causality among messages and have no counterpart in the much simpler unidirectional case.
Giorgia Marson is a researcher in the security group of NEC Laboratories Europe, Heidelberg, since November 2017. Before joining NEC she was a postdoc at the Horst-Görtz Institute for IT security of Ruhr University Bochum, working in the Crypto team of Eike Kiltz. She received her PhD from TU Darmstadt, where she worked in Marc Fischlin's team Cryptoplexity. Giorgia is interested in cryptography, with focus on provable security, in information security, and in distributed systems.