Talk by visiting Professor Christopher Brzuska on State-separation for game-playing proofs

Abstract: We start our talk by reflections on the similarity between (some) game-based and (some) simulation-based definitions. We then explain shortly how a typical game-playing proof for a real-life protocol such as TLS looks like and why/how we reach limits of human understanding quickly in such proofs.  

We then present a new technique to carry out game-playing proofs: We here package pieces of code that share state and allow information between packages only to flow via calls. Thereby, we obtain a call graph where the packages are the nodes. We then show how reductions can be represented via cuts in the graph and show proof examples that become more manageable when thinking on the level of packages rather than on the level of individual code lines.

In the end of the seminar, we would like to discuss the complexity of MPC proofs with the audience.

Speaker: Visiting professor Christopher Brzuska http://www.chrisbrzuska.de/ (The Cryptography and Security Group is hosting)