Description
Un certain nombre de cryptanalyses sur les algorithmes de chiffrement à flot peuvent s'exprimer comme des problèmes de correction d'erreurs et bénéficient par conséquent des progrès réalisés dans le domaine du décodage. Dans cet exposé, nous présenterons plusieurs attaques sur les systèmes par registre filtré qui reposent toutes sur l'existence de relations linéaires creuses entre les bits de la suite à filtrer. Nous montrerons comment ces relations peuvent être exploitées par les techniques de décodage itératif que nous analyserons en détail.
Next sessions
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    Lie algebras and the security of cryptosystems based on classical varieties in disguiseSpeaker : Mingjie Chen - KU Leuven In 2006, de Graaf et al. proposed a strategy based on Lie algebras for finding a linear transformation in the projective linear group that connects two linearly equivalent projective varieties defined over the rational numbers. Their method succeeds for several families of “classical” varieties, such as Veronese varieties, which are known to have large automorphism groups. In this talk, we[…]- 
                                        
    
    Cryptography 
 
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    Some applications of linear programming to DilithiumSpeaker : Paco AZEVEDO OLIVEIRA - Thales & UVSQ Dilithium is a signature algorithm, considered post-quantum, and recently standardized under the name ML-DSA by NIST. Due to its security and performance, it is recommended in most use cases. During this presentation, I will outline the main ideas behind two studies, conducted in collaboration with Andersson Calle-Vierra, Benoît Cogliati, and Louis Goubin, which provide a better understanding of[…]
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    Wagner’s Algorithm Provably Runs in Subexponential Time for SIS^∞Speaker : Johanna Loyer - Inria Saclay At CRYPTO 2015, Kirchner and Fouque claimed that a carefully tuned variant of the Blum-Kalai-Wasserman (BKW) algorithm (JACM 2003) should solve the Learning with Errors problem (LWE) in slightly subexponential time for modulus q = poly(n) and narrow error distribution, when given enough LWE samples. Taking a modular view, one may regard BKW as a combination of Wagner’s algorithm (CRYPTO 2002), run[…]- 
                                        
    
    Cryptography 
 
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    CryptoVerif: a computationally-sound security protocol verifierSpeaker : 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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    Structured-Seed Local Pseudorandom Generators and their ApplicationsSpeaker : Nikolas Melissaris - IRIF We introduce structured‑seed local pseudorandom generators (SSL-PRGs), pseudorandom generators whose seed is drawn from an efficiently sampleable, structured distribution rather than uniformly. This seemingly modest relaxation turns out to capture many known applications of local PRGs, yet it can be realized from a broader family of hardness assumptions. Our main technical contribution is a[…]- 
                                        
    
    Cryptography 
 
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