Delay Tolerant Networks (DTNs) are a sub-class of mobile ad hoc networks (MANETs). They are mobile wireless networks that feature inherent connection disruption. In particular such networks are generally non-connected. In this paper we focus on defining a broadcast service which operate on DTNs. A number of protocols solving the problem of broadcasting across DTNs have been proposed in the past...

We propose a membership and a reliable broadcast protocol that support several diierent semantics simultaneously and provide good overall performance. The broadcast protocol supports three atomicity semantics|weak, strong, and strict atomicity|and three ordering semantics| unordered, total order, and time order. These result in nine group communicationsemantics and an application can dynamicall...

We revisit the following question: what is the optimal round complexity of verifiable secret sharing (VSS)? We focus here on the case of perfect VSS where the number of corrupted parties t satisfies t < n/3, with n the total number of parties. Work of Gennaro et al. (STOC 2001) and Fitzi et al. (TCC 2006) shows that, assuming a broadcast channel, 3 rounds are necessary and sufficient for effici...

Vehicular Ad-Hoc Network (VANET) is an prominent new technology develop in ad hoc network, wireless local area network i.e WLAN and cellular technology to achieve intelligent intervehicle communications ,improve road traffic safety and improve the efficiency .Within a given geographical region broadcast based geocast enable to provide efficient data dissemination to vehicle. Broadcast based geo...

Data broadcasting provides an effective way to disseminate information in the wireless mobile environment using a broadcast channel. How to provide the service of the k nearest neighbors (kNN) search using data broadcasting is studied in this paper. Given a data set D and a query point p, the kNN search finds k data points in D closest to p. By assuming that the data is indexed by an R-tree, we...

The exchange of total order broadcast protocols for dependable applications has been already studied and solved in several previous papers. To this end, some switching mechanism is needed. All these solutions have been inspired in a two-phase algorithm. The first phase is needed to agree on the need of change, stopping then the old protocol. Whilst the second one is needed to wait for the deliv...