GTACS

Title: Quantum circuits for binary elliptic curve arithmetic

Speaker: Pierre-Louis Cayrel (Université Jean Monnet in Saint-Etienne)

Title: Recent progress in code-based cryptography

The annual workshop of the Check Point Institute for Information Security (CPIIS) brings together students and practitioners in the area of cryptography and information security, for sharing of recent research and current perspective.

Details and schedule: http://cpiis.cs.tau.ac.il/cryptosec2012

It is well known that it is impossible for two parties to toss a coin fairly (Cleve, STOC

Motivated by recent developments in fully homomorphic encryption, we consider the folklore conjecture that every semantically-secure bit-encryption scheme is circular secure, or in other words, that every bit-encryption scheme remains secure even when the adversary is given encryptions of the individual bits of the private-key. We show the following obstacles to proving this conjecture:

Probabilistically Checkable Proofs (PCPs) allow a verifier
to check the validity of a proof by querying very few random
positions in the proof string. Zero Knowledge (ZK) Proofs allow a
prover to convince a verifier of a statement without revealing any
information beyond the validity of the statement. We study for what
class of languages it is possible to achieve both, namely to build
ZK-PCPs, where additionally we require that the proof be generated

We revisit the question of whether cryptographic protocols can replace correlated equilibria mediators in two-player games. This problem was first addressed by Dodis, Halevi and Rabin (CRYPTO 2000), who suggested replacing the mediator with a secure protocol and proved that their solution is stable in the Nash equilibrium (NE) sense, provided that the players are computationally bounded.

The traditional notion of program obfuscation requires that an obfuscation P' of a program P computes the exact same function as P, but beyond that, the code of P' should not leak any information about P. This strong notion of virtual black-box security was shown by Barak et al. (CRYPTO 2001) to be impossible to achieve, for certain unobfuscatable function families.

joint work with Yoni Moses

***13:30 Please note the unusual time.***