Invited Lectures

We are pleased to announce the invited lectures of SAC 2013:

  • Paulo S. L. M. Barreto, University of São Paulo, Brazil
    The realm of the pairings
    Abstract: Bilinear maps, or pairings, initially proposed in a cryptologic context for cryptanalytic purposes, proved afterward to be an amazingly flexible and useful tool for the construction of cryptosystems with unique features. Yet, they are notoriously hard to implement efficiently, so that their effective deployment requires a careful choice of parameters and algorithms. In this talk I review the development of efficient algorithms for pairing-based cryptosystems, the state-of-the-art in pairing computation, and the challenges yet to be addressed on the subject, also presenting some new algorithmic refinements in affine and projective coordinates.

  • Anne Canteaut, INRIA Paris-Rocquencourt, France
    Similarities between encryption and decryption: how far can we go?
    Abstract: In this talk, I will investigate some approaches for reducing the hardware footprint of a block cipher for different constraints of the targeted applications. In this context, I will focus on the strategies which can be used for minimizing the overhead for decryption on top of encryption. These strategies include involutive ciphers and the construction used in PRINCE. In particular, I will discuss the potential weaknesses which might be introduced by this type of constructions.

  • Antoine Joux, CryptoExperts and Université de Versailles Saint-Quentin-en-Yvelines, France
    Revisiting discrete logarithms in small/medium characteristic finite fields
    Abstract: In this talk, we present a new algorithm for the computation of discrete logarithms in finite fields of small characteristic. This algorithm combines several previously existing techniques with a few additional ingredients. Among those, the most notable is: A new method for generating multiplicative relations with a "systematic side" by composing the polynomial (X^q-X) with homographies.
    Composing this with improved descent techniques, we show how to achieve an asymptotic complexity L(1/4+o(1)) for discrete logs in GF(q^k) where k is close to q and achieve new record computations. The asymptotic complexity can further be improved to quasi-polynomial time using an asymptotically better but less practical descent method.

  • Douglas R. Stinson, University of Waterloo, Canada
    Key distribution in wireless sensor networks
    Abstract: The seminal 2002 paper of Eschenauer and Gligor proposed a randomized key distribution scheme for wireless sensor networks, wherein each node in the network is pre-loaded with a random subset of $k$ nodes chosen from a certain key pool. These keys are used to enable symmetric-key cryptographic operations between nodes that share one or more keys. The goal is that the resulting network should have a satisfactory degree of connectivity, yet at the same time be resilient to an adversary that captures some number of nodes and extracts the keys in them. The Eschenauer-Gligor paper has led to a large amount of research on the construction and analysis of these types of key distribution schemes. There has been considerable interest in recent years in deterministic schemes, which are typically constructed using suitable combinatorial structures such as codes or designs. In this talk, I will provide an introduction and peregrination of various aspects of key distribution in wireless sensor networks, including a comparison of the strengths and weaknesses of randomized and combinatorial schemes. As well, I will discuss some new results on the flexibility of combinatorial schemes with regard to how their parameters can be chosen to adapt to wide variety of security and performance requirements.

  • Hugh C. Williams, Director, The Tutte Institute for Mathematics and Computing, Ottawa, Canada
    The Tutte Institute for Mathematics and Computing
    Abstract: The Tutte Institute for Mathematics and Computing (TIMC) is a recently established research institute within the Communications Security Establishment Canada (CSEC). We conduct classified research in fundamental mathematics, computer science and engineering with a focus in three areas: Cryptology, Knowledge Discovery/Data Mining and cyber security. In order to accomplish this, we need to attract and engage Canadian researchers to work in support of the Canadian security and intelligence community to obtain the highest possible return on research partnerships within the allied cryptologic community. While the objectives of TIMC may seem to be somewhat narrow, it must be emphasized that we need to enlist the talents of many people within a very wide spectrum of mathematical interests and capabilities. The purpose of this talk is to describe TIMC to the cryptologic research community. The objectives of TIMC, its possible connections to academic institutions and how individual researchers outside of TIMC can make a contribution to its mission will be described.