Catálogo de publicaciones - libros

Dynamism of mobile ad-hoc networks implies changing trust relationships among their nodes that can be established using peer-to-peer PKIs. Here, certification paths can be built although part of the infrastructure is temporarily unreachable because there can be multiple paths between two entities but certification path discovery is difficult since all the options do not lead to the target entity. On the contrary, in hierarchical PKIs, there is only one path between two entities and certification paths are easy to find. For that reason, we propose a protocol that establishes a virtual hierarchy in a peer-to-peer PKI. The results show that this protocol can be executed in a short time. In addition, our protocol does not require to issue new certificates among PKI entities, facilitates the certification path discovery process and the maximum path length can be adapted to the characteristics of users with limited processing and storage capacity.

The IEEE 802.15.4 specification is a recent low data rate wireless personal area network standard. While basic security services are provided for, there is a lack of more advanced techniques which are indispensable in modern personal area network applications. In addition, performance implications of those services are not known. In this paper, we describe a secure data exchange protocol based on the Zigbee specification and built on top of 802.15.4 link layer. This protocol includes a key exchange mechanism. Then, we evaluate the overhead of this scheme under different application scenarios. Initial results show the range of network and traffic parameters wherein the proposed scheme is feasible to use.

The growing popularity of wireless ad hoc networks has brought increasing attention to many security issues for such networks. A lot of research has been carried out in the areas of authentication and key management for such networks. However, due to lack of existing standards for such networks, most of the proposed schemes are based on different assumptions and are applicable only in specific environments. Recently Balachandran et al. proposed CRTDH [1], a novel key agreement scheme for group communications in wireless ad hoc networks. The protocol has many desirable properties such as efficient computation of group key and support for high dynamics. However, the protocol does not discuss mutual authentication among the nodes and hence, suffers from two kinds of attacks: man-in-the-middle attack and Least Common Multiple (LCM) attack. This paper identifies the problems with the current CRTDH scheme and discusses these attacks. AUTH-CRTDH, a modified key agreement protocol with authentication capability, is also presented. Results from extensive experiments that were run on the proposed protocol and some other key agreement protocols including CRTDH are also discussed. It can be observed from the experiments that the new scheme is comparable with the CRTDH scheme and better than many other non-authenticated schemes in terms of performance.

The nature of mobile ad-hoc networks does not permit a member of the group or a central authority to determine a single key to be used among the group members. Group key agreement offers a solution to this problem by allowing the group members to collaboratively determine the common key for the group. Additionally, authenticated group key agreement (AGKA) is an important issue in many modern collaborative and distributed applications. During the last few years, a number of authenticated group key agreement protocols have been proposed in the literature. In this paper, we present a secure ID-based AGKA protocol which only requires by using pairing-based cryptography. We prove that the scheme is secure against an active adversary under the decisional bilinear Diffie-Hellman assumption in the Random Oracle Model. We then extend our scheme to a two-round AGKA protocol which is more efficient in communication costs, and this scheme outperforms any existing AGKA protocols in the literature.

In this paper, we propose an efficient augmented password-based encrypted key exchange protocol based on that of Bellovin and Merritt. The protocol is more efficient than any of the existing augmented encrypted key exchange protocols in the literature we can document and thus is popular in low resource environments. Furthermore, we have proved its security under the assumptions that the hash function closely behaves like a random oracle and that the computational Diffie-Hellman problem is difficult.

Relative location information is very useful in vehicular networks although it is vulnerable to various attacks. Many techniques have been proposed for relative positioning and location verification. Due to the high speed and the strict security requirements, the existing relative positioning and location verification techniques are not directly applicable to vehicular networks. Hence we present a scheme called , which securely determines the relative locations of a set of wirelessly connected vehicles based on the relative locations of each vehicle’s surrounding vehicles. uses cryptographic keys to authenticate location messages and uses a vehicle’s public key to identify the vehicle while protecting drivers’ privacy. To defend against Sybil attacks, employs registration and ticket verification mechanisms. It defends Wormhole and black hole attacks by probabilistically monitoring losses of relative location messages. Analysis and simulation results show that is lightweight and is resilient to Sybil, Wormhole and some other attacks.

Energy efficiency is a major design issue in wireless ad hoc networks since nodes are battery constrained. In such a network each node has to support, in addition to the application workload, the one resulting from the lack of any infrastructure or centralized administration in the network. In particular far-off communications between nodes are done using a multi-hop route via other nodes. Thus they may decide to relay or not packets, but using an inappropriate routing approach can sunk the performances. In this paper we propose a distributed local-control algorithm that guarantees a fair workload distribution across the network. This approach ensures that each node will contribute proportionally to its available energy. Furthermore, the algorithm is able to deal with dynamic networks like mobile ad hoc networks (MANETs). We study the relevance of our approach to prolong the lifetime in dynamic heterogeneous networks through simulations using OMNeT++.

Geographic routing is one of the most widely-accepted techniques to route information in large-scale wireless sensor networks. It is based on a greedy forwarding strategy by which a sensor node selects as next hop relay the most promising neighbor (according to some metric) among those being closer to the destination than itself. This decision is based solely on the position of its neighbors and the destination. Given that sensor nodes are usually operated by batteries, energy-efficiency is a very important metric to be considered by the routing protocol. In this paper we present Locally-Optimal Source Routing (LOSR), a new localized and energy-efficient geographic routing algorithm for wireless sensor networks. Unlike existing energy-efficient geographic routing algorithms, in which current node routing the packet only considers nodes closer to destination than itself, LOSR uses all nodes in the neighborhood to compute a local energy-optimal path formed only by neighbors of the current node towards the selected next hop. Then, is used to force data packets to follow that locally optimal path until next hop is reached. Our simulation results show that the proposed algorithm outperforms the best existing solution, over a variety of network densities and scenarios.

We consider the problem of sensor data collection in a wireless sensor network (WSN). The geographic deployment of sensors is random, with an irregular network topology. We propose a data collection scheme for the WSN, based on the concept of the in graph theory. The purpose of the scheme is to use less power in the process of data collection. Because it is mostly true that the sensors of WSN are powered by batteries, power saving is an especially important issue in WSN. In this paper, we will propose the energy-saving scheme, and provide the experimental results. It is shown that under the energy consumption model used in the paper, the proposed scheme saves about 20% of the power collecting data from sensors.

Wireless sensor networks are being deployed in many monitoring scenarios as fundamental data collection protocols are becoming efficient in handling simple sense-and-send function. As the computation capacity of sensor nodes grows, these nodes are capable of performing more complicated functions. Moreover, the need to realize the complete loop of sense-control-actuate as the wired sensing facility demands for more in-network processing to be able to generate meaningful in-network actuation. One such useful primitive function for many applications is edge or boundary detection of a phenomenon. In this work, we propose a localized edge detection algorithm using basic geometry rules that just uses one-hop neighbourhood information. This algorithm is accordingly benchmarked against one of the best localised edge detection scheme available in the public domain. It is found that the proposed algorithm readily outperforms its counterpart. Moreover, its energy efficient operation is attractive as a primitive implementation for other more complex primitives or applications themselves.