Description
The security of modern cryptosystems relies on computational assumptions, which may be challenged by the advent of large-scale quantum computing devices.<br/> While Shor's algorithm is known to break today's most popular public-key schemes, secret-key cryptosystems are generally expected to retain half of their pre-quantum bits of security. However, the precise advantage of quantum attacks cannot be determined without a dedicated analysis.<br/> In this talk, we will focus on key-recovery attacks against block ciphers. These attacks are often categorized in two scenarios, depending on the type of black-box access allowed to the adversary: either a classical query access, or a "quantum" query access where the black-box is part of the adversary's quantum algorithm. Attacks with classical queries, which are deemed more realistic, have so far complied with the rule of halving security levels.<br/> On the contrary, attacks with quantum queries can break some classically secure designs which exhibit a strong algebraic structure (Kuwakado & Morii, ISIT 2010).<br/> Exploiting this structure with classical queries only was the goal of the offline-Simon algorithm of Bonnetain et al. (ASIACRYPT 2019). In the final part of this talk, we will show that this algorithm allows to reach a more than quadratic speedup against some specific block cipher constructions. This is joint work with Xavier Bonnetain and Ferdinand Sibleyras.<br/> lien: https://univ-rennes1-fr.zoom.us/j/97066341266?pwd=RUthOFV5cm1uT0ZCQVh6QUcrb1drQT09
Next sessions
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SoK: Security of the Ascon Modes
Speaker : Charlotte Lefevre - Radboud University
The Ascon authenticated encryption scheme and hash function of Dobraunig et al (Journal of Cryptology 2021) were recently selected as winner of the NIST lightweight cryptography competition. The mode underlying Ascon authenticated encryption (Ascon-AE) resembles ideas of SpongeWrap, but not quite, and various works have investigated the generic security of Ascon-AE, all covering different attack[…] -
Comprehensive Modelling of Power Noise via Gaussian Processes with Applications to True Random Number Generators
Speaker : Maciej Skorski - Laboratoire Hubert Curien
The talk examines power noise modelling through Gaussian Processes for secure True Random Number Generators. While revisiting one-sided fractional Brownian motion, we obtain novel contributions by quantifying posterior uncertainty in exact analytical form, establishing quasi-stationary properties, and developing rigorous time-frequency analysis. These results are applied to model oscillator[…]-
Cryptography
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TRNG
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CryptoVerif: a computationally-sound security protocol verifier
Speaker : Bruno Blanchet - Inria
CryptoVerif is a security protocol verifier sound in the computational model of cryptography. It produces proofs by sequences of games, like those done manually by cryptographers. It has an automatic proof strategy and can also be guided by the user. It provides a generic method for specifying security assumptions on many cryptographic primitives, and can prove secrecy, authentication, and[…]-
Cryptography
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