Pascal Berthomé

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This paper presents a new decomposition technique for hierarchical Cayley graphs. This technique yields a very easy implementation of the divide & conquer paradigm for weak order problems on very complex architectures as the Star graph or the Pancake. As applications, we introduce asymptotically optimal algorithms for Broadcasting, Gossiping, and Semigroup(More)
Smart card software has to implement software countermeasures to face attacks. Some of these attacks are physical disruptions of chip components that cause a misbehavior in the code execution. A successful functional attack may reveal a secret or grant an undesired authorization. In this paper, we propose to model fault attacks at source level and then(More)
This paper presents several deterministic algorithms for selecting the k th largest record from a set of n records on any n -node hypercubic network. All of the algorithms are based on the selection algorithm of Cole and Yap, as well as on various sorting algorithms for hypercubic networks. Our fastest algorithm runs in O( lg n lg * n) time, very nearly(More)
One of the most important threats for Android users is the collection of private data by malware put on the market. Most of the proposed approaches that help to guarantee the user's privacy rely on modified versions of the Android operating system. In this paper, we propose to automatically detect when an application accesses private data and to log this(More)
To ensure the privacy of users in transport systems, researchers are working on new protocols providing the best security guarantees while respecting functional requirements of transport operators. In this paper , we design a secure NFC m-ticketing protocol for public transport that preserves users’ anonymity and prevents transport operators from tracing(More)
Smart card programs are subject to physical attacks that disturb the execution of the embedded code. These attacks enable attackers to steal valuable information or to force a malicious behavior upon the attacked code. This paper proposes a methodology to check interval security properties on smart card source codes. The goal is to identify critical attacks(More)