Chafika Benzaid

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Group communication is an abstraction which deals with multicasting a message from a source process to a group of processes. In Group Communication Systems (<i>GCS</i>), causal message ordering is an essential tool to ensure interaction among group members in a consistent way. In this paper, we propose a simple and optimal causal multicast protocol which(More)
This paper presents, Mobi_Causal, a new protocol to implement causal ordering in mobile computing systems. The implementation of causal ordering proposed in this paper uses the new timestamping mechanisms proposed by Prakash and Singhal for mobile environments; dependency sequences and hierarchical clocks. Our protocol, compared with previous proposals, is(More)
Broadcast authentication is a fundamental security service in wireless sensor networks (WSNs). Although symmetric-key-based μTESLA-like schemes were employed due to their energy efficiency, they all suffer from DoS attacks resulting from the nature of delayed message authentication. Recently, several public-key-based schemes were proposed to achieve(More)
Most wireless sensor network (WSN) applications require a synchronized local clock in sensor nodes. One promising approach to achieve time synchronization in WSN, with significantly reduced energy consumption, is the Receiver-Only synchronization approach. However, to the best of our knowledge, there has been no previous published work addressing the(More)
In this paper, we propose a simple and optimal causal broadcast protocol which copes with the dynamically changing groups in mobile environments. The protocol depends on two simples, yet powerful ideas. The first consists in the use of the <i>immediate dependency relationship</i> (<i>IDR</i>) in the construction of control information (<i>CI</i>), resulting(More)
In Group Communication Systems (GCS), causal message ordering is an essential tool to ensure interaction among group members in a consistent way. In several group-based applications, the exchanged information is often diffused to all members. Using a multicast protocol to ensure this broadcast should make the definition of data structures not optimal for(More)
In wireless sensor networks (WSNs), it may be necessary to have a unified time reference for all network nodes. Such a necessity may be imposed by the management strategy in the network, e.g., using time based medium access arbitration, or simply due to the dynamic nature of the application, e.g. target tracking. Since each node more or less operates(More)
Broadcast authentication is a fundamental security service in wireless sensor networks (WSNs). Although symmetric-key-based &#x03BC;TESLA-like schemes were employed due to their energy efficiency, they all suffer from DoS attacks resulting from the nature of delayed message authentication. Recently, several public-key-based schemes have been proposed to(More)
This paper proposes an Enhanced Secure Pairwise Broadcast Time Synchronization (E-SPBS) protocol that allows authenticated MAC-layer timestamping on high-data rate radio interfaces. E-SPBS ensures the security of the Receiver-Only synchronization approach using a Public-Key-based Cryptography authentication scheme. The robustness and accuracy of E-SPBS were(More)