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)


Claude Crépeau (#352)
Name Claude Crépeau
Personal Homepage
Topic of his/her doctorate. Correct and Private Reduction among Oblivious Transfers
Category cryptographic protocols
Keywords Quantum Cryptography
Ph.D. Supervisor(s) Silvio Micali
Year of completion 1990
Abstract Roughly speaking a protocol is a way of exchanging messages so that each party gains some specified information. Correctness and privacy are fundamental constraints to the notion of a secure protocol. Essentially, correctness guarantees that the information the parties learn in executing a protocol is what was specified. Privacy guarantees that they cannot learn more than that.

We investigate correctness and privacy for the primitive notion of oblivious transfer protocols. As introduced by Rabin, in an oblivious transfer a party S (the sender) owning a secret message m discloses this message to another party R (the receiver) with probability 1. S does not find out whether R did get the message or not. A different 2 version of this notion (1-out-of-2-oblivious transfer) was introduced by Even, Goldreich and Lempel. Traditionally, correctness and privacy were guaranteed assuming that the parties had bounded computational resources and that some appropriate mathematical problems were intractable.

We formalize these and other notions of oblivious transfer in abstract setting, without assuming any computational restrictions on the participants. We also formalize the notion of a reduction, that is a method by which one form of oblivious transfer can be achieved under the assumption that another form exists abstractly. We then show correct and private reductions between various notions of oblivious transfer. Some of these notions arise naturally in a physical scenario.
E-Mail Address crepeau (at)
Last Change 2011-04-16 13:54:38
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Claude Crépeau's Students

Mohamed Layouni - Privacy-preserving Personal Information Management (cryptographic protocols)

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