SAC 2015 Program
Stafford Tavares Lecture
Title: Trust Aware Traffic Security
Presenter: Paul Syverson
Abstract:
We will trace the development of trust-aware traffic security in onion routing networks 2009‒2015.
Beginning with the question of how to mathematically model diversity of trust across an onion routing network,
we will also discuss defining adversaries for a trust-aware context, representing trust in a usable way,
accounting for all the network elements to which trust might be assigned, and making use of trust to design
more secure routing.
SAC Invited Talk
Title: Generic Attacks against MAC Algorithms
Presenter: Gaëtan Leurent
Abstract:
In this talk we will discuss the security of some classical MAC constructions based on block ciphers or hash functions.
These construction are widely deployed, and their security has been proven based on idealized behavior of the underlying primitive.
We will focus on generic attacks and how the relate to the complexity bounds of the security proof. The two approaches are complementary: generic attacks yields upper bounds on the security of a mode, and security proofs yield a lower bound. While there is usually an attack matching the proof, we point out that this only the case for the strongest security notion, resistance against existential forgery. For weaker security notions, there is usually a gap between the best attacks and the complexity bound of the proof, and the security loss when the bounds are exceeded is not well understood. Actually, constructions with similar security proofs can have very different security levels beyond the bound.
In particular, we will discuss recent attacks against hash-based MACs, showing that state recovery and universal forgery attacks require less than 2n work.