In this paper, we introduce a new scheme that allows transmission from a set of asynchronous transmitters to a remote destination which, otherwise, would not be capable to forward the data individually. In our scheme the small devices form an Opportunistic Large Array (OLA) by reacting to the signal sent by a special node in the network, called the leader. The problem solution provides as a byp...

Network traffic encryption is becoming a requirement, not an option. Enabling encryption will be a communal effort so a solution that gives partial benefits until fully deployed is needed. A solution that requires little changes to existing infrastructure will also help as it can be quickly deployed to give immediate shortterm benefits. We argue that tcpcrypt, a TCP option for opportunistic enc...

We present LOT, a lightweight ‘plug and play’ secure tunneling protocol deployed at network gateways. Two communicating gateways, A and B, running LOT would automatically detect each other and establish an efficient tunnel, securing communication between them. LOT tunnels allow A to discard spoofed packets that specify source addresses in B’s network and vice-versa. This helps to mitigate many ...

Opportunistic networks enables mobile users to participate in social interactions through applications such as content distribution, flea-market, micro-blogs and round based games. To interact securely, the establishment of trust is vital in a distributed environment. Trust is required to validate an identity and avoid sybil users, select trustworthy interaction partners or to collect useful op...

In Opportunistic Networks (OppNets), mobile devices transmit messages by exploiting the direct contacts, without the need of an end-to-end infrastructure. Disconnections of nodes and high churn rates are normal features of opportunistic networks. Hence, routing is one of the main challenges in this environment. In this article, we provide a survey of the main routing approaches in OppNets and c...

This book contains a collection of 32 papers presented at the 19th Annual Clinical Conference on Cancer (1974) of the University of Texas, MD Anderson Hospital and Tumor Institute. Twentytwo of the papers were contributed by members of the local hospital staff. The conference was intended to emphasize the expanding role of cancer chemotherapy in the management of cancer patients, and 16 papers ...

In this paper we present an approach to support privacy in opportunistic sensing. In particular, we use compact and privacy preserving representations of data (or sketches), that allow us to compute relevant statistics over data without disclosing users’ sensitive information (e.g. locations). We exemplify our approach by referring to the important application of noise pollution monitoring. We ...

In opportunistic routing, each node maintains a group of candidate relays to reach a particular destination, and transmits packets to any node in this group. If a single candidate relay receives the packet, it becomes the effective relay to forward the packet further. If no candidate receives the packet, then the current sender re-transmits. If multiple candidates receive the packet, then the l...

Building semantically annotated corpora from scratch is a time consuming activity requiring very specialized resources. In this paper we present a pilot study carried out to test a methodology that can be used to create a semantically annotated corpus by exploiting information contained in an already annotated corpus. The main hypothesis underlying the proposed methodology is that, given a text...