International Association for Cryptologic Research

Ph.D. Database

The aim of the IACR Ph.D. database is twofold. On the first hand, we want to offer an overview of Ph.D. already completed in the domain of cryptology. Where possible, this should also include a subject classification, an abstract, and access to the full text. On the second hand, it deals with Ph.D. subjects currently under investigation. This way, we provide a timely map of contemporary research in cryptology. All entries or changes need to be approved by an editor. You can contact them via phds (at)


Pierre-Alain Fouque (#312)
Name Pierre-Alain Fouque
Personal Homepage
Topic of his/her doctorate. Le partage de clés cryptographiques: Théorie et Pratique
Ph.D. Supervisor(s) Jacques Stern
Year of completion 2001
Abstract The cryptography aims at protecting communications against different kinds of adversaries. Threshold cryptography allows on the one hand, to share the decryption or signature power amongst several servers, and on the other hand, to consider adversaries that may attack many servers. These kinds of attacks are realistic in practical applications requiring a high security level. Threshold cryptography designs secure and efficient protocols against these adversaries. It is between the cryptography area and multiparty computation which allows to distribute the calculation of some functions. In this thesis, we have dealt with the problem of complete distributed protocols without requiring a trusted dealer at any moment. After some results and facts of cryptography and threshold cryptography, we have presented such a protocol for the RSA scheme. Then, we have proposed the complete sharing of Paillier cryptosystem against different kinds of attackers. Next, we have proposed a variant of a distributed key generation for Diffie-Hellman keys. Finally, we have showed in the third party that the different kinds of sharing of the homomorphic cryptosystem of Paillier are needed in order to take into account the requirements of high-level schemes such as lottery, electronic voting or key recovery systems.
Last Change 2011-04-19 04:02:55
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Pierre-Alain Fouque's Students

Charles Bouillaguet - Some attacks against hardness assumptions and cyptographic primitives
Gaëtan Leurent - Design and Analysis of Hash Functions (secret-key cryptography)

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