Igor Monteiro Moraes

FITS: A flexible virtual network testbed architecture

In this paper, we present the design and implementation of FITS (Future Internet Testbed with Security), an open, shared, and general-purpose testbed for the Future Internet. FITS defines an innovative architecture that allows users running experiments with new mechanisms and protocols using both Xen and OpenFlow on the same network infrastructure. FITS integrates several recognized state-of-the-art features such as plane separation, zero-loss network migration, and smartcard-driven security access, to cite a few. The current physical testbed is composed of nodes placed at several Brazilian and European institutions interconnected by encrypted tunnels. Besides presenting the FITS architecture and its features, we also discuss deployment challenges and how we have overcome them.

LPS and LRF: Efficient buffer management policies for Delay and Disruption Tolerant Networks

In Delay and Disruption Tolerant Networks (DTNs), the message delivery rate is impacted by the buffer management policy adopted by nodes once buffer overflows occur frequently. This paper proposes two new buffer management policies. The first one, called LPS (Less Probable Sprayed), uses the messages delivery probability and estimates the number of replicas already disseminated to decide which message to drop. The second one, named LRF (Least Recently Forwarded), drops the least recently forwarded message based on the assumption that messages not forwarded over a certain period of time have already reached several next hops. These two policies are implemented and compared with existing proposals found in the literature. The analysis considers traces of three real networks in which LPS and LRF policies provide higher delivery rates up to 75% and 37%, respectively, than the rate provided by the second best policy, with less overhead.

Challenges and Research Directions for the Future Internetworking

We review the main challenges and survey promising techniques for network interconnection in the Internet of the future. To this end, we first discuss the shortcomings of the Internets current model. Among them, many are consequence of unforeseen demands on the original Internet design such as: mobility, multihoming, multipath, and network scalability. These challenges have attracted significant research efforts in the latest years because of both their relevance and complexity. In this survey, for the sake of completeness, we cover several new protocols for network interconnection spanning both incremental deployments (evolutionary approach) and radical proposals to redesign the Internet from scratch (clean-slate approach). We focus on specific proposals for future internetworking such as: Loc/ID split, flat routing, network mobility, multipath and content-based routing, path programmability, and Internet scalability. Although there is no consensus on the future internetworking approach, requirements such as security, scalability, and incremental deployment are often considered.

On the performance of a secure storage mechanism for key distribution architectures in wireless sensor networks

Security in wireless sensor networks (WSNs) demands efficient key management schemes. In particular, one of the main research challenges is to ensure secure key storage by sensors due to their constrained resources and high exposure to tampering attempts. To address this issue, we have proposed SENSORLock, a secure key storage mechanism which can be applied to different key distribution architectures for WSNs. In this work, we evaluate SENSORLock through different study cases considering three key distribution architectures: TinySec, SPINS, and NCD. Our goal is to demonstrate its feasibility in large-scale sensor networks. Simulation results indicate that our mechanism introduces an average overhead of 1.9% in terms of end to end delay and provides a similar estimated power consumption compared to the aforementioned architectures. Hence, we argue that it is feasible to use SENSORLock (i) in large-scale sensor networks and (ii) under different key distribution schemes.

SENSORLock: a lightweight key management scheme for wireless sensor networks†

Security in wireless sensor networks demands an efficient key management scheme. As sensors typically operate unattended, it becomes quite important to ensure security to cryptographic keys stored in their memories. In this scenario, the development of lightweight encryption mechanisms is a challenge because of sensor-constrained resources. In this work, we present a mechanism tailored to sensor networks called SENSORLock applying it to a specific case. Our main contribution is to propose, analyze, and demonstrate the feasibility of SENSORLock for secure symmetric key distribution solving the stored key exposure problem. Analytical results demonstrate that this approach increases the systems security against the tampering of sensor nodes. Additionally, the mechanism is evaluated using simulation and practical experiments, using the TinyOS platform. Simulation results reveal that this scheme introduces very low processing overhead, in the order of nanoseconds, and an estimated power consumption quite similar to existing approaches. Besides, practical experiments indicate that the scheme can be deployed by off-the-shelf sensors, such as MicaZ and TelosB. Copyright

Link quality estimation for AMI

An important application in Smart Grids is the Advanced Metering Infrastructure (AMI). Under AMI, utilities use smart meters and aggregators to collect consumer data that support better-informed and automated decisions. AMIs are typically formed by wireless links, reducing the investments in infrastructure. Although beneficial, the use of wireless raise issues of reliability and coverage, and requires the estimation of the success rate in delivering packages. This paper discusses the application of the Extended Hata-SRD propagation model in urban, suburban and rural scenarios, for IEEEs 802.11g and 802.15.4, to determine the success rate of packets exchanged between meters and aggregators.

A forwarding strategy based on reinforcement learning for Content-Centric Networking

This paper proposes a packet forwarding strategy for Information-Centric Networking. Our proposal is based on reinforcement learning techniques and aims at balancing the exploration of new paths and exploiting the data acquired from previous explorations. The output interfaces of a node are classified according to the content retrieval time and all interests that share the same prefix with contents previously forwarded are sent through the interface with the lowest mean retrieval time. The exploration of new paths is probabilistic. Each node sends the same interest through the best interface and through another interface chosen at random simultaneously. The goal is to retrieve the content by using the best path found until present moment and at the same time explore copies that are recently stored in the cache of nearest nodes. Simulation results show that the proposed strategy reduces up to 28% the number of hops traversed by received contents and up to 80% the interest load per node in comparison to other forwarding strategies.

Limiting the interest-packet forwarding in information-centric wireless mesh networks

This paper proposes three mechanisms in order to reduce the broadcast storm problem in information-centric wireless mesh networks. The first one defines a probability to forward interest packets. The second one limits the number of interest packets forwarded based on the number of previous forwarding actions of these packets. The third one is a hybrid approach that combines the forwarding criteria of the two previous mechanisms. The performance of a information-centric wireless mesh networks is evaluated with the three proposed mechanisms and also with the default forwarding mechanism. The performance of such network is also compared with the one provided by a wireless mesh network based on the TCP/IP stack running the OLSR protocol. Results show the proposed mechanisms provide a delivery rate four times higher than the one provided by OLSR. In addition, our proposals outperform the default forwarding mechanism by up to 19% in terms of data delivery rate in dense scenarios with high number of hops between source and destination.

Analyzing the ACK Counterfeiting Attack in Delay and Disruption Tolerant Networks

The routing protocols proposed for Delay and Disruption Tolerant Networks (DTNs) often employ acknowledgements. The goal is to increase the available space in buffers and also to avoid messages from being dropped unnecessarily due to buffer overflow. Protocols that employ such technique, however, are prone to suffer with from the acknowledgement counterfeiting attack. In this attack, malicious nodes counterfeit acknowledgements in order to force legitimate nodes to drop messages that are not already delivered to destination. Thus, the network performance is degraded. In this work, we analyze a countermeasure for this attack, in which nodes ignore acknowledgements for messages that were not previously received by this node. Three real mobility traces and a well-known mobility model are used in simulations and results show that when approximately 12% of the nodes in the network are malicious, the message delivery rate decreases up to 61 percentage points.

Robust Advanced Metering Infrastructures and Networks for Smart Grid

This chapter provides a comprehensive discussion on fault tolerance and reliability for advanced metering infrastructure (AMI) communication. The AMI is one of the main applications in smart grids, and several references have discussed performance requirements for its correct functioning. While, in isolation, the requirements for each user are not high, the scale and density of the network make meeting them a challenge. Moreover, any downtime for this network is harmful, which strongly suggests the need for some degree of fault tolerance. In this chapter, we will discuss the main enabling technologies and architectures for AMI communication, highlighting the currently dominating architecture, based on wireless communication between meters and data aggregation points (DAPs). In this architecture, we will discuss fault tolerance and reliability under the prism of routing (e.g., choosing reliable paths, fast reroute in case of failures, and multipath routing). We will also show how those routing approaches depend on particular topological characteristics of the communication network, which can be guaranteed by proper network planning.