Cédric Lauradoux

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Relay attacks pose a real threat to the security of wireless communications. Distance bounding protocols have been designed to thwart these attacks. In this paper, we study the way to adapt distance bounding protocols to time-hopping ultra wide band (TH-UWB) radios. Two protocols are proposed which are based on the milestones of the TH-UWB radio: the(More)
The F-FCSR family of algorithms have been presented about one year ago with [2] and [1]. While some flaws where found in the initial propositions (on the IV-setup procedure, and a TMD tradeoff attack), there are yet no known weaknesses of the core of these algorithms. We sum up here some of the properties of the automaton that are better understood now, and(More)
Sosemanuk is a new synchronous software-oriented stream cipher, corresponding to Profile 1 of the ECRYPT call for stream cipher primitives. Its key length is variable between 128 and 256 bits. It accommodates a 128-bit initial value. Any key length is claimed to achieve 128-bit security. The Sosemanuk cipher uses both some basic design principles from the(More)
Many distance bounding protocols appropriate for RFID technology have been proposed recently. However, the design and the analysis of these protocols are not based on a formal perspective. Motivated by this need, a formal framework is presented that helps the future attempts to cryptanalyze and design new distance bounding protocols. We first formalize the(More)
The Feedback with Carry Shift Registers (FCSRs) have been proposed as an alternative to Linear Feedback Shift Registers (LFSRs) for the design of stream ciphers. FCSRs have good statistical properties and they provide a built-in non-linearity. However, two attacks have shown that the current representations of FCSRs can introduce weaknesses in the cipher.(More)
Decim is a new stream cipher designed for hardware applications with restricted resources. The design of the cipher is based on both a nonlinear filter LFSR and an irregular decimation mechanism recently introduced and called the ABSG. Apart from the security aspects, the design goal is to produce a stream cipher with a compact hardware implementation and(More)
Many distance bounding protocols appropriate for the RFID technology have been proposed recently. Unfortunately, they are commonly designed without any formal approach, which leads to inaccurate analyzes and unfair comparisons. Motivated by this need, we introduce a unified framework that aims to improve analysis and design of distance bounding protocols.(More)
Feedback with Carry Shift Registers (FCSRs) are a promising alternative to LFSRs in the design of stream cipher. The previous constructions based on FCSRs were dedicated to hardware applications [3]. In this paper, we will describe X-FCSR a family of software oriented stream cipher using FCSRs. The core of the system is composed of two 256-bits FCSRs. We(More)