# Description

The seminar addresses current research on information security and cryptography, both from a theoretical and a practical perspective.

# Registration

The organizational meeting took place on Wednesday, October 22 and **registration for the seminar is now closed**.
Guests are welcome during the presentation sessions.

# Prerequisites

There are no formal requirements for participation. Students should be familiar with basic topics in computer security and cryptography.

Participation in the organization meeting and all the presentation sessions is mandatory.

# Requirements for obtaining credit points (Scheinvergabe)

The seminar requires both an individual contribution by every participant and a contribution achieved within a team of four people (formed by the speakers of each session).

As far as the individual part is concerned, each participant

- is assigned a research paper
that she/he has to present
in the class.
In order to avoid
misunderstandings regarding the presentation of the assigned paper
and to have possible questions answered,
**each participant must have a first version of her/his slides and arrange a meeting with her/his adviser at least two weeks prior to her/his talk; (i.e. 9th of January)** - has to read and understand the papers assigned to the other members of her/his team. Team members will always be assigned papers of similar topic in order to deepen their understanding in the respective area.

The group part requires the team

- to come up with novel research ideas in the respective topic on which the team has been assigned papers. These ideas do not have to constitute outstanding research achievements, but they should be novel in the sense that they complement some of the existing works in some nice fashion;
- to present these novel ideas after the individual talks in the session. The ideas will then be discussed in the class, with a couple of ideas being collaboratively chosen as the ones that look the most promising and that could be pursued further by the team;
- to work out the details of the selected idea and obtain some results by the end of the term;
- to document the results in a scientific form, using appropriate math and illustrating examples where necessary. As a guideline, the overall extent of the report should be about 15-20 pages when typeset with LaTeX in 11pt font. (For reference the reports from last year are available here.)

You must submit (1) your team report as one LaTeX source and in PDF format, as well as (2) the final version of your slides, before the end of term. All team reports and presentation slides will be made available on this Web site.

# Presentation Sessions

All presentation sessions will be held Friday, the 23rd of January.

Each presentation has been
allocated 30 minutes. The length of each talk should be 25 minutes, while
the remaining 5 minutes will be used for questions and comments. We would like this to
be a seminar that participants can profit from, so **the main emphasis of
the talks must be on being understandable**.

Additionally, after the talks of each session the team has allocated 15 minutes to present a list of potentially interesting, scientifically novel ideas, for discussing them in the class, and for identifying the most promising ideas on which the team could work on further.

# Topics/Sessions and Papers

### Topic 1: Authorization Logics

abandoned

### Topic 2: Rational Cryptography

**Final Report**: A Rational Secret Sharing Scheme Robust Against Malicious Players, by Nadja Altabari, Anton Krohmer, Hendrik Molter, and Thorsten Tarrach

Bridging Game Theory and Cryptography: Recent Results and Future Directions. Jonathan Katz. Proceedings of the Fifth Theory of Cryptography Conference (TCC 2008), 2008.

*Speaker: Anton Krohmer*(slides)Cryptography and Game Theory: Designing Protocols for Exchanging Information. Gillat Kol and Moni Naor. Proceedings of the Fifth Theory of Cryptography Conference (TCC 2008), 2008.

*Speaker: Hendrik Molter*(slides)Lower Bounds on Implementing Robust and Resilient Mediators. Ittai Abraham and Danny Dolev and Joseph Y. Halpern. Proceedings of the Fifth Theory of Cryptography Conference (TCC 2008), 2008.

*Speaker: Nadja Altabari*(slides)A Cryptographic Solution to a Game Theoretic Problem. Yevgeniy Dodis and Shai Halevi and Tal Rabin. Proceedings of the 20th International Cryptology Conference (Crypto 2000), 2000.

*Speaker: Thorsten Tarrach*(slides)

Advisers: Oana Ciobotaru and Michael Backes

### Topic 3: Side-channel Attacks

**Final Report**: Yes We Can: Uncovering Spoken Phrases in Encrypted VoIP Conversations, by Goran Doychev, Dominik Feld, Jonas Eckhardt, and Stephan Neumann

Remote Timing Attacks are Practical. David Brumley and Dan Boneh. In Proc. 12th USENIX Security Symposium, 2003.

*Speaker: Jonas Eckhardt*(slides)Hidden Markov Model Cryptanalysis. Chris Karlof and David Wagner. In Proc. Workshop on Cryptographic Hardware and Embedded Systems (CHES), 2003.

*Speaker: Stephan Neumann*(slides)Spot me if you can: Uncovering spoken phrases in encrypted VoIP conversations. Charles Wright, Lucas Ballard, Scott Coull, Fabian Monrose, Gerald Masson. In Proc. IEEE SSP 2008.

*Speaker: Goran Doychev*(slides)Timing Analysis of Keystrokes and Timing Attacks on SSH. Dawn Xiaodong, Song David Wagner, Xuqing Tian. Proc. of USENIX Security Symposium 2001.

*Speaker: Dominik Feld*(slides)

Advisers: Boris Köpf and Markus Dürmuth

### Topic 4: Observational Equivalence for Security Protocols

**Final Report**: Automated Checking of Observational Equivalence for an Extended Spi Calculus, by Georgel Calin, Markus Rabe, and Raphael Reischuk

A Bisimulation Method for Cryptographic Protocols. Martín Abadi and Andrew D. Gordon. Nordic Journal of Computing, 1998.

*Speaker: Georgel Calin*(slides)Automated Verification of Selected Equivalences for Security Protocols. Bruno Blanchet, Martín Abadi, and Cédric Fournet. Journal of Logic and Algebraic Programming, 2008.

*Speaker: Markus Rabe*(slides)A Complete Symbolic Bisimilarity for an Extended Spi Calculus. Johannes Borgström. 6th International Workshop on Security Issues in Concurrency (SecCo'08), 2008.

*Speaker: Raphael Reischuk*(slides)Symbolic Bisimulation for the Applied Pi Calculus. Stéphanie Delaune, Steve Kremer, and Mark Ryan. In Proc. of Foundations of Software Technology and Theoretical Computer Science, 27th International Conference (FSTTCS 2007), 2007.

*Speaker: none*

Advisers: Matteo Maffei and Catalin Hritcu