Section: New Results

Security

Participants : Jean-Marie Gorce, Cédric Lauradoux, Marine Minier, Fabrice Valois, Wassim Znaidi, Ahmed Benfarah, Ochirkhand Erdene-Ochir, Yuanyuan Zhang.

Security is an important issue for wireless networks, especially for wireless sensor networks facing an amizing increase of the number of nodes. We review in this section all contributions related to the security issue, some of them being strongly related with the PHY layer or the networking protocols. As it can be seen below, some results are strongly connected to the models and protocols derived in the other sections.

In [59] , we provide the first independent analysis of the (2^nd-round tweaked) 256-bit version of the SHA3 candidate SHAvite-3. By leveraging recently introduced cryptanalysis tools such as rebound attack or Super-Sbox cryptanalysis, we are able to derive chosen-related-salt distinguishing attacks on the compression function on up to 8 rounds (12 rounds in total) and free-start collisions on up to 7 rounds. In particular, our best results are obtained by carefully controlling the differences in the key schedule of the internal cipher. Most of our results have been implemented and verified experimentally.

In [50] , we study a class of insider attacks called the terrorist fraud. This is a relay attack against distance bounding protocols where the prover conspires with an adversary to misrepresent the distance between himself and the verifier. In ideal situations, the adversary does not gain any knowledge about the prover's long-term secret. This makes designing a distance bounding protocol resistant to such fraud tricky: the secrets of an honest prover must be protected, while those of a dishonest one should be disclosed as an incentive not to cheat. We demonstrate that using a secret-sharing scheme, possibly based on threshold cryptography, is well suited for thwarting the terrorist fraud. Although such an idea has been around since the work of Bussard and Bagga, this is the first time that secret-sharing and terrorist fraud have been systematically studied altogether.

In [40] , we deal with the problem of radio jammiing. Jamming is a major threat against wireless communications. In this paper, we evaluate the effect of jamming on an UWB link employing a PPM non-coherent receiver. We optimize the jammer parameters that are the central frequency and the bandwidth based on the metric of the signal-to-jamming ratio. The optimization depends on different system parameters such as the channel model and the integration time of the receiver.

In [23] , we focus on the resiliency of wireless sensor network routing protocols against selective forwarding attacks by compromised nodes. Informally, resiliency should be understood as the capacity of the routing protocol to endure and mitigate the presence of a certain number of compromised nodes seeking to disturb the routing process. To provide for security when nodes may be compromised, cryptographic solutions must be completed by algorithmic solutions considering “beyond cryptography” approaches. After discussing the shortcomings of existing routing protocols against packet-dropping malicious nodes we describe some protocol behaviors enhancing routing resiliency under several combined routing attacks. We propose in this paper the behaviors enhancing the resiliency of routing protocols under several combined routing attacks.