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In a Nutshell

I successfully defended my PhD thesis on the 14th of November 2008 and I am now a researcher of Prof. Serge Vaudenay's Cryptography and Security Laboratory (LASEC) at EPFL, Switzerland. My main research areas cover block ciphers and their cryptanalysis.

I take part in the teaching activity of the laboratory I work for. I am one the co-authors of an exercise book on cryptography.

I am one of the two developers of iChair, a free server-side software used to manage the submission/review process of a conference.

I obtained a Master Diploma from the Communication Systems section at EPFL in 2004.

Last Update: November 07, 2009

PhD Thesis

Quantitative security of block ciphers : designs and cryptanalysis tools

(Very Short) Abstract: Block ciphers probably figure in the list of the most important cryptographic primitives. Although they are used for many different purposes, their essential goal is to ensure confidentiality. This thesis is concerned by their quantitative security, that is, by measurable attributes that reflect their ability to guarantee this confidentiality.

Download: [Full Text (3.2MB)] [Table of Contents and Abstract] [Slides (private defense)] [Slides (public defense)]

FSE 2008

Co-Chairing the Fast Software Encryption 2008 workshop in Lausanne

I am one of two General Chairs of [FSE 2008] that will be held in Lausanne in February, 2008. FSE 2008 is the 15th annual Fast Software Encryption workshop. It is sponsored by the International Association for Cryptologic Research ([IACR]). Original research papers on symmetric cryptology are invited for submission to [FSE 2008]. The workshop concentrates on fast and secure primitives for symmetric cryptography, including the design and analysis of block ciphers, stream ciphers, encryption schemes, analysis and evaluation tools, hash functions, and message authentication codes (MACs).

Of course, we use [iChair] to manage the submission and the review processes.

Research Articles

The Complexity of Distinguishing Distributions

Thomas Baignères and Serge Vaudenay

Published in the Proceedings of ICITS 08 (Calgary, Canada)

Download: [pdf]

Linear Cryptanalysis of Non Binary Ciphers (with an Application to SAFER)

Thomas Baignères, Jacques Stern, and Serge Vaudenay

Published in the Proceedings of SAC 07 (Ottawa, Canada)

Download: [ps] [pdf] [slides]

KFC - The Krazy Feistel Cipher

Thomas Baignères and Matthieu Finiasz

Published in the Proceedings of Asiacrypt'06 (Shanghai, China)

Download: [ps] [pdf] [bibtex] [slides]

Dial C for Cipher

Thomas Baignères and Matthieu Finiasz

Published in the Proceedings of SAC 06 (Montreal, Canada)

Download: [ps] [pdf] [slides]

Proving the Security of the AES Substitution-Permutation Network

Thomas Baignères and Serge Vaudenay

Published in the Proceedings of SAC 05 (Kingston, Canada)

Download: [ps] [pdf] [bibtex] [slides]

How Far Can We Go Beyond Linear Cryptanalysis?

Thomas Baignères, Pascal Junod, and Serge Vaudenay

Published in the Proceedings of Asiacrypt'04 (Jeju Island, Korea)

Download: [ps] [pdf] [bibtex] [slides]

Book

A Classical Introduction to Cryptography: Exercise Book

Thomas Baignères, Pascal Junod, Lu Yi, Jean Monnerat, and Serge Vaudenay

Published by Springer-Verlag. More details on the web site of the book.

iChair

iChair is a powerful submission/review server software designed to help the program chair of a conference with submission collection, assignments of articles to reviewers, review collection, discussions, mailing, ...

iChair was developed with a view to being as easy to install as possible. As a result, installation on a Linux box should be possible by anyone (even with only basic knowledge of server administration) in about one or two hours. It might even be possible to run it on a windows based server (but this was never tested). It was developed in PHP5 and intended to run on an apache web server.

iChair has already been used for several conferences, including CrapOCrypt 2006 (a fake test conference), Eurocrypt 2006, ANTS VII, ACISP 2006, Crypto 2006, SAC 2006, ICISC 2006, Vietcrypt 2006, CANS 06, Asiacrypt 2006, Inscript 2006, Pairing 2007, Indocrypt 2006, PKC 2007, ISPEC 2007, ACISP07, FSE 2007, WISTP 2007, WCC 2007, CARDIS 2008, Inscrypt 2007, WAIFI 2007, ICITS, Kryptographie - Theorie und Praxis, Provable Security 2007, IWSEC 2007, Special Issue on Cryptography in Computer System Security, WISSec 2007, International Conference on Information Theoretic Security, Cryptography and Coding, CANS 2007, AfricaCrypt 2008, FSE 2008,  ...

If you want to use iChair for one of your conferences, you should contact me or Matthieu Finiasz.

Invited Talks, Tutorials & Other Reports

Talk at the "Université Catholique de Louvain":

Thomas Baignères

These are the slides of a presentation I made on the 5th of February 2009 at the [Université Catholique de Louvain], where I was invited by [Prof. Gildas Avoine] from the [Information Security Group].

Download: [pdf] [keynote08 (zip file)] [html]

Practical Decorrelation

Thomas Baignères

These are the slides of a presentation I made at ESC'08 in January. The talks is basically a survey on Serge Vaudenay's decorrelation theory and on how we (with Matthieu Finiasz) used it to prove the security of two block ciphers constructions, namely C and KFC.

Download the slides: [pdf]

Flash version: [flash]

Provable Security in Cryptography

Thomas Baignères

This tutorial is a compilation of some of my readings while I was preparing two lectures given at EPFL on provable security in cryptography. The topics covered include the basic security definitions for public-key & signature schemes, an introduction to game playing techniques, and several practical examples of proofs using games: ElGamal encryption, RF/RP Lemma, the Luby-Rackoff construction, the Full Domain Hash (FDH), and OAEP+.

Download: [ps] [pdf]

Cryptosystems and LLL

Thomas Baignères

Report realized during Prof. Amin Shokrollahi's lectures on Algorithmic Number Theory. It provides a survey on lattices, LLL, and on two attacks proposed by Phong Nguyen on the GGH cryptosystem and on the implementation of El Gamal signatures in GPG 1.2.3.

Download: [ps] [pdf] [slides]

Quantum Cryptography: On the Security of the BB84 Key-Exchange Protocol

Thomas Baignères

Report realized during Prof. Arikan's lectures on Quantum Computation and Quantum Information.

Download: [ps] [pdf] [slides]

A Generalization of Linear Cryptanalysis

Thomas Baignères

Master Thesis realized at the Cryptography & Security Laboratory (LASEC), EPFL, under the supervision of Prof. Vaudenay.

Download: [ps] [pdf] [slides]

Factorisation de Grands Nombres à l'Aide de Courbes Elliptiques

Thomas Baignères

Undergraduate semester project on the ECM method. This project was realized under the supervision of Jean Monnerat in March 2003.

Download (in French): [ps] [pdf] [slides]

Attaque à Texte Chiffré Choisi contre PKCS#1

Thomas Baignères

Undergraduate semester project on Daniel Bleichenbacher's attack against the RSA encryption standard. This project was realized under the supervision of Pascal Junod in 2002.

Download (in French): [ps] [pdf] [slides]