Utilisation de l'envoi multichemins disjoints pour la securite de reseaux ad-hoc mobiles

Mobility has become a main feature for several applications and computer networks are not an exception. In fact, computing which is more and more present and essential find its limits when it has to move.; The lack of a wide spread infrastructure such as the one we call find in cellular networks, leaded to set up mobile networks without any fixed infrastructure commonly named Ad-hoc mobile networks or MANETs. Originally, those networks were designed for military applications and emergency situations such as natural disasters where an important need to share information without any predefined infrastructure is present to he extended to more conventional applications such as meetings, forums, etc.; Mobile Ad-hoc networks consist of a collection of wireless mobile nodes self-organised and without any predefined infrastructure, exchanging data among themselves without the reliance on a fixed base station or a wired backbone network. Nodes also assume the packets routing task. This particularity allows nodes to communicate further than their limited antenna range and gain flexibility without limiting the network size.; This concept, very different from the conventional networks, presents a real improvement to the wireless networking field. Unfortunately, it also presents several weaknesses mostly related to data security.; In this thesis, we tried to solve the data, security problem and specially data integrity in the mobile ad-hoc networks. We propose a strategy consisting in developing a secure protocol based on the multipath disjoined nodes routing to preserve the data integrity from modification.; Our approach consists in using a particular MANET property traduced by the availability of a multiple different and node disjoint routes from a source node to a destination one. The proposed protocol finds and maintains a set of routes between a source and a destination node. It then uses a subset of those routes to send data and creates a redundancy allowing the integrity check. The redundancy data consist in the hash of each sent packet. Due to their little sizes, the hashes prevent the network congestion.; The disjoint nodes routing protocol provide a security against the presence of the same malicious node on two or more different routes. This strategy forces the attacker to deploy more than one network node and to insure their collaboration for any eventual successful attack. This task is not as easy as it sounds to be and needs a colossal deployment effort to guaranty any attack feasibility.; To evaluate the performances of the proposed protocol SDMRP (Secure Disjoint Multipath Routing Protocol), we implemented it and simulated a series of experiments and scenarios. We focused our experimental effort on evaluating the probability of a successful attack and the mean end to end latency. We compared our protocol to AODV (Ad-hoc On-demand Distance Vector routing) which was used as a basis to build SDMRP.; We have obtained interesting results, in particular for the probability of attack success which decreases as we increase the number of used routes. The mean end to end latency was also reduced compared with AODV.