687 results

• • Seminar

  • Cryptography

  Beyond the black and grey box

  • April 25, 2014

  • IRMAR - Université de Rennes - Campus Beaulieu Bat. 22, RDC, Rennes - Amphi Lebesgue

  Speaker : Yoni De Mulder - University of Leuven

  In the white-box attack context, i.e., the setting where an implementation of a cryptographic algorithm is executed on an untrusted open platform, the adversary has full access to the implementation and its execution environment. As a result, the adversary is much more powerful than in a traditional black-box environment in which the adversary has only access to the inputs and outputs of a[…]

• • Seminar

  • Cryptography

  A heuristic quasi-polynomial algorithm for discrete logarithm

  • October 03, 2014

  • IRMAR - Université de Rennes - Campus Beaulieu Bat. 22, RDC, Rennes - Amphi Lebesgue

  Speaker : Razvan Basbulescu - LORIA

  in finite fields of small characteristic The difficulty of discrete logarithm computations in fields GF(q^k) depends on the relative sizes of k and q. Until recently all the cases had a sub-exponential complexity of type L(1/3), similar to the complexity of factoring. If n is the bit-size of q^k, then L(1/3) can be approximated by 2^(n^(1/3)). In 2013, Joux designed a new algorithm for constant[…]

• • Seminar

  • Cryptography

  Cryptanalysis of Round-Reduced PRINCE and TWINE

  • March 27, 2015

  • IRMAR - Université de Rennes - Campus Beaulieu Bat. 22, RDC, Rennes - Amphi Lebesgue

  Speaker : Patrick Derbez - Luxembourg

  NXP Semiconductors and its academic partners challenged the cryptographic community with finding practical attacks on the block cipher they designed, PRINCE. In the first part of this talk we present new attacks on round-reduced PRINCE including the ones which won the challenge in the 6 and 8-round categories --- the highest for which winners were identified. Our first attacks rely on a meet-in[…]

• • Seminar

  • Cryptography

  Chiffrement (complètement) homomorphe : de la théorie à la pratique

  • June 20, 2014

  • IRMAR - Université de Rennes - Campus Beaulieu Bat. 22, RDC, Rennes - Amphi Lebesgue

  Speaker : Tancrède Lepoint - CryptoExperts

  Le chiffrement complètement homomorphe (parfois considéré comme le Saint Graal de la cryptographie) permet d'effectuer (de façon publique) des calculs arbitraires sur des messages chiffrés. Les premières instanciations de cette surprenante primitive ne peuvent être considérées comme pratiques, chaque multiplication de deux bits chiffrés nécessitant d'être suivie par une procédure de plusieurs[…]

• • Seminar

  • Cryptography

  Cyclic and quasi-cyclic separable Goppa codes

  • November 14, 2014

  • IRMAR - Université de Rennes - Campus Beaulieu Bat. 22, RDC, Rennes - Amphi Lebesgue

  Speaker : Sergey Bezzateev - Université d'État de Saint-Pétersbourg

  Overview of recent results in constructions of cyclic and quasi-cyclic Goppa codes. Classical and generalized Goppa codes are considered. Subclasses of embedded optimal quasi-cyclic Goppa codes with improvement parameters are presented.

• • Seminar

  • Cryptography

  Keep your friends close with distance-bounding protocols

  • February 07, 2014

  • IRMAR - Université de Rennes - Campus Beaulieu Bat. 22, RDC, Rennes - Amphi Lebesgue

  Speaker : Maria Cristina Onete - IRISA

  Authentication protocols, run between a prover and a verifier, allow the verifier to check the legitimacy of the prover. A legitimate prover should always authenticate (the correctness requirement), while illegitimate parties (adversaries) should not authenticate (the soundness or impersonation resistance requirement). Secure authentication protocols thwart most Man-in-the-Middle (MIM) attacks,[…]