649 results

  • A Compositional and Complete approach to Verifying Privacy Properties using the Applied Pi-calculus

    • February 08, 2019

    • Inria Center of the University of Rennes - - Room TBD

    Speaker : Ross Horne (University of Luxembourg)

    The pi-calculus was introduced for verifying cryptographic protocols by Abadi and Fournet in 2001. They proposed an equivalence technique, called bisimilarity, useful for verify privacy properties. It is widely acknowledged (cf. Paige and Tarjan 1987), that bisimilarity is more efficient to check than trace equivalence; however, surprisingly, tools based on the applied pi-calculus typically still[…]
  • Number Systems and Cryptography, some examples

    • February 08, 2019

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

    Speaker : Jean-Claude Bajard - Sorbonne Université

    Number systems are behind a lot of implementations. The role of representation is often underrated while its importance in implementation is crucial. We survey here some classes of fundamental systems that could be used in crypotgraphy. We present three main categories:<br/> - systems based on the Chinese Remainder Theorem which enter more generally in the context of polynomial interpolation,<br/[…]
  • CSIDH: an efficient post-quantum commutative group action

    • February 01, 2019

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

    Speaker : Chloé Martindale - Technical University of Eindhoven

    CSIDH, or `commutative supersingular isogeny Diffie-Hellman' is a new isogeny-based protocol of Castryck, Lange, Martindale, Panny, and Renes.<br/> The Diffie-Hellman style scheme resulting from the group action allows for public key validation at very little cost, runs reasonably fast in practice, and has public keys of only 64 bytes at a conjectured AES-128 security level, matching NIST’s post[…]
  • Towards Non-Interactive Zero-Knowledge from CDH and LWE

    • January 18, 2019

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

    Speaker : Geoffroy Couteau - Karlsruher Institut für Technologie (KIT)

    We provide a generic construction of non-interactive zero-knowledge (NIZK) schemes. Our construction is a refinement of Dwork and Naor’s (FOCS 2000) implementation of the hidden bits model using verifiable pseudorandom generators (VPRGs). Our refinement simplifies their construction and relaxes the necessary assumptions considerably. As a result of this conceptual improvement, we obtain[…]
  • Privacy in The 5G-AKA Authentication Protocol

    • January 18, 2019

    • Inria Center of the University of Rennes - - Room TBD

    Speaker : Adrien Koutsos (LSV)

    The 5G mobile communications standards are being finalized, and drafts are now available. This standard describes the 5G-AKA authentication and key exchange protocol. The previous version of AKA (3G and 4G) are well-known for their lack of privacy against an active adversary (e.g. a user can be massively tracked using IMSI-catcher). This new version of AKA tries to offer more privacy, notably[…]
  • Wave: A New Code-Based Signature Scheme

    • January 11, 2019

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

    Speaker : Thomas Debris-alazard - inria

    It is a long standing open problem to build an efficient and secure digital signature scheme based on the hardness of decoding a linear code which could compete with widespread schemes like DSA or RSA. The latter signature schemes are broken by a quantum computer with Shor’s algorithm. Code-based schemes could provide a valid quantum resistant replacement. We present here Wave the first « hash[…]