Smart card are often the target of software or hardware attacks. For instance the most recent attacks are based on fault injection which can modify the behavior of applications loaded in the card, changing them as mutant application. In this paper, we propose a new protection mechanism which makes application to be less prone to mutant generation. This countermeasure requires a transformation of the original program byte codes which remains semantically equivalent. It requires a modification of the Java Virtual Machine which remains backward compatible and a dedicated framework to deploy the applications. Hence, our proposition improves the ability of the platform to resist to Fault Enabled Mutant.

Virtual machine monitor is a hot topic in the embedded community. Apart from high end system, current processors for embedded systems do not have any instructions helping to virtualize an operating system. Based on this fact, most of the current hypervisors for embedded devices use the Para virtualization technique. This is the case of the OKL4 kernel which is based on the L4 micro-kernel and implements among other the Linux kernel as guest OS. We introduce our ongoing work for testing the security of OKL4. We have chosen to focus on the most low level OKL4 interface usable from an external actor: the system call API. Because all operating system components use directly or indirectly these system calls, a minor flaw at this level can impact in chain the entire system including a virtualized kernel. We have developed a model describing the OKL4 system calls. This model also contains all constraints applicable to a system call. Based on these models, we are working on a tool using the constraints to compute a reduced set of system call input values which are highly likely to generate flaws in OKL4 if they are not fully checked by the hypervisor.

Currently, NFC phones are coming in the handheld market, providing facilities to perform m-transactions. Obviously, this type of operation requires special security precautions. Indeed, a malicious code could intercept and hijack the system, even if there is a smart card. For example, the amount of the payment displayed in the terminal can be hijacked by an attacker to fool the user, or user's credential can be stolen thanks to a keylogger (and thus malicious codes can perform unwanted m-transactions automatically). This paper describes a security mechanism based on a graphical Turing test to prevent m-transactions submission by malwares. Firstly it introduces current m-transactions solutions. Then it explains the security mechanism that we propose to tackle the problem of untrusted handheld devices. It also underlines a proof of concept we implemented, to test its feasibility on a SIM card. Finally, it gives information on performances corresponding to the implementation that we made.

We propose several localized algorithms to achieve energy-efficient broadcasting in wireless multihop networks using directional antennas. Each node needs to know only geographic position of itself and its neighbors. Our first protocol is called DRBOP and it follows the one-to-one communication model to reach to all nodes in the relative neighborhood graph (RNG). Each node that receives a message for the first time from one of its RNG neighbors will rebroadcast it to each of its remaining RNG neighbors separately. The transmission power is adjusted for each transmission to the minimal necessary for reaching the particular neighbor. Next, we describe DLBOP, where RNG is replaced by the localized minimum spanning tree (LMST) graph which is a localized topology resembling the minimum spanning tree. We then observe that, for very dense networks, it is more energy-efficient to reach more than one neighbor at a time. A one-to-many protocol efficient for dense networks is proposed. We then describe an efficient localized protocol which adaptively switches (without any threshold) between one-to-one and one-to-many communication models and is efficient for both sparse and dense networks. Our simulation results show that for different energy models, the adaptive protocol is able to achieve a competitive performance to globalized algorithms while having a fully localized operation.

Among all the security issues in Voice over IP (VoIP) communications, one of the most difficult to achieve is traffic analysis resistance. Indeed, classical approaches provide a reasonable degree of security but induce large round-trip times that are incompatible with VoIP. In this paper, we describe some of the privacy and security issues derived from traffic analysis in VoIP. We also give an overview of how to provide low-latency VoIP communication with strong resistance to traffic analysis. Finally, we present a server which can provide such resistance to hundreds of users even if the server is compromised.

This paper presents a fully decentralized distributed path reservation system for a group of asynchronous cooperative mobile robots. The protocol assumes a mobile ad hoc network formed by the robots themselves, and takes advantage of the inherent locality of the problem in order to reduce communication. In contrast with other work, our protocol requires neither initial nor complete knowledge of the composition of the group. A performance analysis of the protocol provides insights for a proper dimensioning of system parameters in order to maximize the average effective speed of the robots

In the minimum energy broadcasting problem, each node can adjust its transmission power in order to minimize total energy consumption but still enable a message originated from a source node to reach all the other nodes in an ad-hoc wireless network. In all existing solutions each node requires global network information (including distances between any two neighboring nodes in the network) in order to decide its own transmission radius. We describe a new localized protocol where each node requires only the knowledge of its distance to all neighboring nodes and distances between its neighboring nodes (or, alternatively, geographic position of itself and its neighboring nodes). In addition to using only local information, our protocol is shown experimentally to be comparable to the best known globalized BIP solution. Our solutions are based on the use of relative neighborhood graph, which preserves connectivity and is defined in localized manner.