Pedro B. Velloso

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In this paper, we propose a human-based model which builds a trust relationship between nodes in an ad hoc network. The trust is based on previous individual experiences and on the recommendations of others. We present the Recommendation Exchange Protocol (REP) which allows nodes to exchange recommendations about their neighbors. Our proposal does not(More)
The current Internet architecture allows malicious nodes to disguise their origin during denial-of-service attacks with IP spoofing. A well-known solution to identify these nodes is IP traceback. In this paper, we introduce and analyze a lightweight single-packet IP traceback system that does not store any data in the network core. The proposed system(More)
Distributed applications use Bloom filters to transmit large sets in a compact form. However, attackers can easily disrupt these applications by using or advertising saturated filters. In this paper we introduce the Generalized Bloom Filter (GBF), a space-efficient data structure to securely represent a set in distributed applications, such as IP traceback,(More)
In this paper we present a new routing paradigm for wireless multihop networks. In plasma routing, each packet is delivered over the best available path to one of the gateways. The choice of the path and gateway for each packet is not made beforehand by the source node, but rather on-the-fly by the mesh routers as the packet traverses the network. We(More)
On most denial-of-service (DoS) attacks, packets with spoofed source addresses are employed in order to disguise the true origin of the attacker. A defense strategy is to trace attack packets back to their actual source in order to make the attacker accountable and isolate him from the network. To date, the proposed traceback systems require either large(More) 1570-8705/ 2014 Elsevier B.V. All rights reserved. ⇑ Corresponding author. Tel.: +55 21 2562 8635. E-mail addresses: (L.H.G. Ferraz), (P.B. Velloso), (O.C.M.B. Duarte). 1 Grupo de Teleinformática e Automação – GTA, Universidade Federal do Rio de Janeiro (UFRJ),(More)
This paper analyzes voice transmission capacity on ad hoc networks by performing simulations related to delay and jitter. We evaluate the influence of QoS provision and mobility on the number of voice transmitting sources. Results show that the maximum number of voice transmissions can be increased when medium access time is reduced by means of a service(More)
This paper presents and analyzes a collision avoidance mechanism that increases the throughput and decreases the delay in wireless local area networks. The analysis considers the IEEE 802.11 standard parameters employed in the Distributed Coordination Function used in the Ad Hoc mode operation. The mechanism is based on the Deferral Counter (DC) algorithm(More)
1389-1286/$ see front matter 2014 Elsevier B.V. All rights reserved. ⇑ Corresponding author. Tel.: +55 21 2629 5679. E-mail addresses: (I.M. Moraes), (D.M.F. Mattos), (L.H.G. Ferraz), (M.E.M. Campista), (M.G. Rubinstein),(More)