627 results
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Group Signatures for Federated Systems
Speaker : Mark Manulis - Ruhr-University of Bochum
For many mutli-party applications group signatures are important cryptographic primitives that can be used for the purpose of anonymity and privacy. In classical group signatures members of a group are able to sign messages anonymously on behalf of the group. However, there exists a designated authority, called group manager, that initializes the scheme, adds new group members, and is able to open[…] -
Le décodage itératif et ses applications à la cryptanalyse
Speaker : Anne Canteaut et Jean-Pierre Tillich - INRIA, projet CODES
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[…] -
Cryptography in the Bounded Quantum-Storage Model
Speaker : Serge Fehr - CWI Amsterdam
Most of todays cryptography relies on the assumption that a potential attacker cannot solve some computational problem (e.g. factor a large integer). It has been shown in the early 80's that with the use of quantum-mechanical effects, certain cryptographic tasks can be done unconditionally, i.e., secure against computationally unbounded attackers: Quantum-cryptography, and with it the hope that (m[…] -
Constructing group based provably secure encryption schemes: a
Speaker : Maria Isabel Gonzalez Vasco - Universidad Rey Juan Carlos Madrid
Cryptographic primitives arising from group theory have in the last few years attracted a lot of attention. Unfortunately, up to date most of the existing proposals are still far away from practical applications, not only due to unlucky computational assumptions which later turned out to be invalid. In this talk we address the impact of modern security analysis in the sense of provable security to[…] -
Métrique rang et applications en cryptographie
Speaker : Pierre Loidreau - ENSTA
Dans cet exposé, on présentera la notion de métrique rang et l'intérêt qu'elle peut représenter dans la conception de systèmes de chiffrement à clé publique fondés sur la théorie des codes correcteurs. Dans un second temps, on exposera divers cryptosystèmes déjà publiés, dont la sécurité repose sur des propriétés de la métrique rang. Le premier type de cryptosystème est un cryptosystème de type[…] -
Protecting security protocols against guessing attacks: towards
Speaker : Mathieu Baudet - ENS Cachan
Designing secure protocols based on passwords is a difficult task. Indeed, passwords, and more generally low-entropy secrets, are potentially vulnerable to guessing attacks, that is, exhaustive, "brute force" searches. Preventing guessing attacks typically requires a protocol to conceal any partial information on the password (e.g. its checksum) which could help the attacker confirm his guess[…]