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In wireless sensor networks, data aggregation protocols are employed to prolong the network lifetime. However, performing data aggregation while preserving security is a challenging problem. This paper presents a polynomial regression based secure data aggregation protocol in which sensor nodes represent their sensed data as polynomial functions. Instead of their original data, sensor nodes secretly...
Most ISPs rely on their upstream providers in achieving global reachability, thus they tend to make backup upstream links for the purpose of improving their own resilience. Yet, the Internet AS topology does not entail as much redundancy as it is widely thought, e.g., in our observation, 23.6% of all ASes only have single provider. Moreover, even though an AS has multiple upstream links, if all its...
We propose EagleEye, an accountable logging framework as a middleware for distributed and networked systems. EagleEye offloads the logging function from the distributed application program so that applications can focus on the logic handling without worrying about when and how to do logging. By capturing and analyzing network packets, EagleEye is able to reproduce the entire networking event history...
In this paper, we propose Accountable MapReduce, which forces each machine to be held responsible for its behavior. We set up a group of auditors to perform an Accountability Test (A-test) which will check all working machines and detect malicious nodes in real time.
In this paper, we propose an implementation scheme of flow-net which is designed to record events and their relations. Different implementation schemes of the flow-net are introduced and compared. Under the collaboration of the nodes in a network, all of the events in the network are recorded and the relations of the events can be clearly described by flow-net. Because of the clear description of...
In the previous work, a novel flow-net methodology for accountability was proposed to build accountable audit data as well as to retrieve useful information by exploring the audit data. In this work, we attempt to instantiate the flow-net methodology in a distributed/networked system by exploiting log files which are recorded locally on each node in the system. To improve the efficiency of retrieving...
In this paper, we explore a quantitative approach to accountable wireless multi-hop networks. We propose using hierarchical P-Accountability to adapt the requirements of modeling a complex network environment and assess the degree of accountability in a fine-grained manner. We have defined P-Accountability and demonstrated its use in the hierarchical network environment. In addition, we apply P-Accountability...
Distributed Coordinate Functions (DCF) is the mandatory medium access method for IEEE 802.11 Wireless Local Area Networks (WLANs), which is designed for infrastructure WLANs where all end users connect with Access Point (AP) with single-hop links. DCF doubles its Contention Window (CW) before each retransmission. However, in multi-hops WLANs, a node may encounter different kinds of transmission failures...
Experiments show that IEEE 802.11 DCF system exhibits unstable behavior in the congestion onset load range where the system starts to become saturated. This phenomenon is not well investigated due to the lack of proper models. In this paper, we propose a two-dimensional (2-D) Markov chain model by combining the well-known saturated model with newly created idle states. Closed-form solution to the...
In this paper, we explore a quantitative approach to accountable networked systems. We propose P-Accountability, a novel concept and general metric, to assess the degree of system accountability. As a preliminary case study, we apply P-Accountability to PeerReview, an accountable distributed system. A quantitative relation between P-Accountability and message loss probability is given. We re-evaluate...
This paper provides parameter setting and 2-D local stability conditions for TCP/RED networks. In general, a network cannot avoid congestions due to the limit of network capacity. The RED scheme is one of the representative AQM that was proposed to avoid and alleviate network congestions. However, the issue of network stability with many TCP subscribers needs to be considered when setting the RED...
To achieve better performance, we adopt a heterogeneous sensor network (HSN) model. In many applications, the locations of some sensor nodes are controllable. In this paper, first we propose a novel density-varying deployment scheme for high-end sensors (H-sensors) in an HSN. The scheme solves the bottleneck problem in typical many-to-one sensor networks. We then study the optimal placement of H-sensors...
Large propagation delay and node movement are considered to be two significant attributes that differentiate an underwater wireless sensor network (UWSN) from a ground wireless sensor network (WSN). Considering the effects of both propagation delay and movement, we propose a time synchronization algorithm suitable for a UWSN. An underwater node can move out of and into another node's range frequently...
Channel capacity and node energy represent resources and constraints in designing efficient routing schemes for Wireless Sensor Networks(WSNs). To delivery more data, a higher rate is desirable, which however consumes more energy and may demand more bandwidth. Hence, data transmission in WSNs should take into account both limited capacity and constrained energy. In this paper, we propose an utility-based...
In this paper, based on our proposed mal-packet self-propagation models in wireless sensor networks, we use TOSSIM to study their propagation dynamics. We also present a preliminary study of the feasibility of mal-packet defense in sensor networks. Specifically, based on random graph theory and percolation theory, we propose the immunization of the highly-connected nodes in order to partition the...
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