On providing location privacy for mobile sinks in wireless sensor networks

A common practice in sensor networks is to collect sensing data and report them to the sinks or to some pre-defined data rendezvous points via multi-hop communications. Attackers may locate the sink easily by reading the destination field in the packet header or predicting the arrival of the sink at the rendezvous points, which opens up vulnerabilities to location privacy of the sinks. In this paper, we propose a random data collection scheme to protect the location privacy of mobile sinks in wireless sensor networks. Data are forwarded along random paths and stored at the intermediate nodes probabilistically in the network. The sinks will move around randomly to collect data from the local nodes occasionally, which prevents the attackers from predicting their locations and movements. We analyze different kind of attacks threatening the location privacy of the sinks in sensor networks. We also evaluate the delivery rate, data collection delay and protection strength of our scheme by both analysis and simulations. Both analytical and simulation results show that our scheme can protect location privacy of mobile sinks effectively, while providing satisfactory data collection services.     

Sink location privacy protection under direction attack in wireless sensor networks

Wireless Sensor Networks have been widely deployed in military and civilian applications. Due to the nature of the sensor network, it is easy for an adversary to trace the movement of packets and get the sink location. Many ways have been proposed to deal with this problem, most of them provide path diversity. But these techniques always expose direction information. Once adversaries have got the direction information, they can launch a direction attack by deducing the direction of the sink and choosing right paths to trace. To cope with the direction attack, we present an improved scheme based on injecting fake packets and random walk of real packets. In this scheme, real packets do a random walk to hide direction information at a special phase, fake packets are injected in intersection nodes of two or more shortest paths, which can lead adversaries to fake paths. Privacy analysis shows that our scheme has a good performance on protecting sink location. We also examine the delivery time, energy consumption and safe time by simulations.     

Design and analysis of novel quorum-based sink location service scheme in wireless sensor networks

Geographic routing in wireless sensor networks requires sources nodes to be aware of the location information of sinks to send their data. To provide the sink location service, quorum-based schemes have been proposed, which exploit crossing points between a quorum of a sink location announcement (SLA) message from a sink and a quorum of a sink location query (SLQ) message from a source node. For guaranteeing at least one crossing point in irregular sensor networks with void areas or irregular boundaries, the previous schemes however collect and flood the network boundary information or forward a SLA and SLQ message along the whole network boundary. In this paper, we design a novel quorum-based sink location service scheme that exploits circle and line quorums, which does not require the network boundary information and send a SLA and SLQ message along the whole network boundary. In the proposed scheme, a source node sends a SLQ message to the network center and sends another SLQ message to an edge node in the network boundary, thus generating a SLQ line quorum. On the other hand, a sink node sends a SLA message along a circle path whose center is the network center, thus forming a SLQ circle quorum. By this way, it is guaranteed that the SLQ and SLA quorums have at least one crossing point in irregular sensor networks. Both numerical analysis and extensive simulation results verify that the proposed scheme outperforms the existing schemes in terms of the delivery distance, the delivery hop count, and the energy consumption for providing sink location service.     

A light-weight authentication scheme for wireless sensor networks

Sensor networks are ad hoc mobile networks that include sensor nodes with limited computational and communication capabilities. They have become an economically viable monitoring solution for a wide variety of applications. Obviously, security threats need to be addressed and, taking into account its limited resources, the use of symmetric cryptography is strongly recommended. In this paper, a light-weight authentication model for wireless sensor networks composed of a key management and an authentication protocol is presented. It is based on the use of simple symmetric cryptographic primitives with very low computational requirements, which obtains better results than other proposals in the literature. Compared to SPINS and BROSK protocols, the proposal can reduce energy consumption by up to 98% and 67%, respectively. It also scales well with the size of the network, due to it only requiring one interchanged message, independently of the total number of nodes in the network.     

A group-based security scheme for wireless sensor networks

In recent years, wireless sensor networks have been a very popular research topic, offering a treasure trove of systems, networking, hardware, security, and application-related problems. Distributed nature and their deployment in remote areas, these networks are vulnerable to numerous security threats that can adversely affect their proper functioning. The problem is more critical if its purpose is for some mission-critical applications such as in a tactical battlefield. This paper presents a security scheme for group-based distributed wireless sensor networks. Our first goal is to devise a group-based secure wireless sensor network. We exploit the multi-line version of matrix key distribution technique and Gaussian distribution to achieve this goal. Secondly, security mechanisms are proposed for such a group-based network architecture in which sensed data collected at numerous, inexpensive sensor nodes are filtered by local processing on its way through more capable and compromise-tolerant reporting nodes. We address the upstream requirement that reporting nodes authenticate data produced by sensors before aggregating and the downstream requirement that sensors authenticates commands disseminated from reporting nodes. Security analysis is presented to quantify the strength of the proposed scheme against security threats. Through simulations, we validate the analytical results.     

A node division location detection scheme for chain‐type wireless sensor networks

As a special type of wireless sensor network, the chain‐type wireless sensor networks can be used to monitor narrow and long regions, such as roads, underground mine tunnels, rivers, and bridges. In this study, a perpendicular bisector division (PB) method was first presented, in which the location may be divided into more location sub‐areas by a perpendicular bisector of each of two location nodes. Compared with the triangulation division method in Approximate Point‐in‐Triangulation Test (APIT), the computable complexity of PB is lower, and the number of division areas is larger. Furthermore, in order to locate targets under rare location nodes, a virtual location node‐perpendicular bisector division (VPB) was presented by a virtual location node based on the geographic shape of the monitored area. Virtual location nodes increase the density of location nodes, which can improve the accuracy of the location in the location algorithm. Second, two range‐free location algorithms were proposed: the location algorithm based on PB (LAPB) and the location algorithm based on VPB (LAVPB). In the end, the location errors performance of APIT, LAPB, and LAVPB for locating miners in an underground mine tunnel was tested. The results show that LAPB and LAVPB have higher location accuracy and are more robust than APIT. LAVPB is more suitable for locating targets in harsh environments. Copyright © 2014 John Wiley & Sons, Ltd.     

A secure channel code‐based scheme for privacy preserving data aggregation in wireless sensor networks

Data aggregation is an efficient method to reduce the energy consumption in wireless sensor networks (WSNs). However, data aggregation schemes pose challenges in ensuring data privacy in WSN because traditional encryption schemes cannot support data aggregation. Homomorphic encryption schemes are promising techniques to provide end to end data privacy in WSN. Data reliability is another main issue in WSN due to the errors introduced by communication channels. In this paper, a symmetric additive homomorphic encryption scheme based on Rao‐Nam scheme is proposed to provide data confidentiality during aggregation in WSN. This scheme also possess the capability to correct errors present in the aggregated data. The required security levels can be achieved in the proposed scheme through channel decoding problem by embedding security in encoding matrix and error vector. The error vectors are carefully designed so that the randomness properties are preserved while homomorphically combining the data from different sensor nodes. Extensive cryptanalysis shows that the proposed scheme is secure against all attacks reported against private‐key encryption schemes based on error correcting codes. The performance of the encryption scheme is compared with the related schemes, and the results show that the proposed encryption scheme outperforms the existing schemes.     

A bio-inspired field estimation scheme for wireless sensor networks

This paper proposes and analyzes a bio-inspired field estimation scheme using wireless sensor networks. The proposed scheme exploits the temporal pattern of the sensed process to reduce the number of samples sent back to the sink by a sensor node and, as consequence, decrease the energy consumption in data transmission. The proposed scheme is orthogonal to the techniques that reduce the spatial density of collected samples deactivating nodes with similar measurements. Thus, the proposed scheme can be used along with these techniques. We present two variations of this scheme: a sample-bounded and an error-bounded. The sample-bounded limits the maximum number of samples sent back to the sink, while the error-bounded guarantees the observation of every event of interest. Results show that for very regular processes the scheme can reduce up to 90% the total amount of samples sent in the network and even for less regular processes the proposed scheme can reduce the total amount of samples sent from approximately 10 up to 20%, with small reconstruction errors.     

无线传感器网络的簇头功率控制技术

在军事侦察与环境监测中,无线传感器网络一般部署在无人区域或危险区域,不能依靠人对系统进行配置与管理.网络节点通过撒播造成分簇后密度不均,影响了网络性能.由于同簇节点通信使用同一信道,簇的大小直接关系到每个节点的通信能力.当簇内节点个数处于一个合适的范围时,网络才能发挥最好的性能.因此需要对簇头进行功率控制来优化网络结构.针对这一缺乏准确数学模型的过程,提出一种基于PID的模糊自适应的变步长簇头功率控制方案,把簇内节点数目控制在一个合理的范围内.其特点是概念简单、易于理解和提高系统的鲁棒性,仿真结果从理论上证明了通过控制分簇大小以后,网络的寿命和通信能力都有所增加.     

Relative location estimation in wireless sensor networks

Self-configuration in wireless sensor networks is a general class of estimation problems that we study via the Cramer-Rao bound (CRB). Specifically, we consider sensor location estimation when sensors measure received signal strength (RSS) or time-of-arrival (TOA) between themselves and neighboring sensors. A small fraction of sensors in the network have a known location, whereas the remaining locations must be estimated. We derive CRBs and maximum-likelihood estimators (MLEs) under Gaussian and log-normal models for the TOA and RSS measurements, respectively. An extensive TOA and RSS measurement campaign in an indoor office area illustrates MLE performance. Finally, relative location estimation algorithms are implemented in a wireless sensor network testbed and deployed in indoor and outdoor environments. The measurements and testbed experiments demonstrate 1-m RMS location errors using TOA, and 1- to 2-m RMS location errors using RSS.     

一种实用的DF协作无线传感器网络跨层设计

针对前向译码(DF)协作无线传感器网络的特点和要求,探讨基于分集合并和差错控制两种技术的实用跨层设计方案。首先,研究支持DF中继协议的协作传感器网络在目的节点采用等增益合并(EGC)的检测方案。通过和传统的最大比合并(MRC)方案以及最近提出的协作MRC方案综合比较,说明等增益合并是一个具有良好性能的实用方案。然后,把物理层的EGC和数据链路层的自动请求重传(ARQ)结合起来,再进行系统分析。最后,基于EGC和截断ARQ提出一种实用跨层设计方案。     

一种用于无线传感器网的协作接收方案

无线传感器网中,能量效率是系统设计首要考虑的因素.基于提高无线传感器网能量效率的目的,本文提出了一种简单的协作接收方案并分析了其能量效率,理论分析及仿真结果表明,当通信距离大于某一门限值时采用该接收方案可以有效提高无线传感器网的能量效率.     

A new hybrid key pre-distribution scheme for wireless sensor networks

This article presents a novel hybrid key pre-distribution scheme based on combinatorial design keys and pair-wise keys. For the presented scheme, the deployment zone is cleft into equal-sized cells. We use the combinatorial design based keys to secure intra-cell communication, which helps to maintain low key storage overhead in the network. For inter-cell communication, each cell maintain multiple associations with all the other cells within communication range and these associations are secured with pair-wise keys. This helps to ensure high resiliency against compromised sensor nodes in the network. We provide in-depth analysis for the presented scheme. We measure the resiliency of the presented scheme by calculating fraction of links effected and fraction of nodes disconnected when adversary compromises some sensor nodes in the network. We find that the presented scheme has high resiliency than majority of existing schemes. Our presented scheme also has low storage overhead than existing schemes.

     

An IPv6 address configuration scheme for wireless sensor networks based on location information

The paper proposes an IPv6 address configuration scheme for wireless sensor networks based on sensor nodes’ location information. The scheme divides WSN into multiple clusters based on sensor nodes’ location information and proposes the IPv6 address structure for sensor nodes based on their location information. In the scheme, a cluster head combines the stateless configuration strategy and the stateful configuration strategy to assign the IPv6 addresses for the cluster members in the same cluster. In the stateless configuration strategy, a cluster head employs the hash division method to configure the IPv6 addresses for the cluster members and utilizes the linear probing method to solve the address collision, and the DAD for the IPv6 addresses assigned for the cluster members is only performed within the cluster where the cluster members locate. In addition, the IPv6 address configuration for the cluster members in the different clusters can be performed simultaneously, so the IPv6 address configuration delay time is shortened and the IPv6 address configuration cost is reduced. The paper analyzes the performance parameters of the proposed scheme, Strong DAD and MANETConf, including DAD cost, address configuration cost and address configuration delay time, and the analytical results show that the performance of the proposed scheme is better than Strong DAD and MANETConf.     

一种实用的DF协作无线传感器网络跨层设计

针对前向译码（DF）协作无线传感器网络的特点和要求,探讨基于分集合并和差错控制两种技术的实用跨层设计方案。首先,研究支持DF中继协议的协作传感器网络在目的节点采用等增益合并（EGC）的检测方案。通过和传统的最大比合并（MRC）方案以及最近提出的协作MRC方案综合比较,说明等增益合并是一个具有良好性能的实用方案。然后,把物理层的EGC和数据链路层的自动请求重传（ARQ）结合起来,再进行系统分析。最后,基于EGC和截断ARQ提出一种实用跨层设计方案。     

Non-interference topology scheme in wireless sensor networks

A novel topology scheme, cell with multiple mobile sinks method (CMMSM), is proposed in this article for the collection of information and for the environment monitoring in wireless sensor networks. The system consists of many static sensors, scattered in a large scale sensing field and multiple mobile sinks, cruising among the clusters. Conservation of energy and simplification of protocol are important design considerations in this scheme. The noninterference topology scheme largely simplifies the full-distributed communication protocol with the ability of collision avoidance and random routing. The total number of cluster heads in such a topology was analyzed, and then an approximate evaluation of the total energy consumption in one round was carried out. Simulation results show that CMMSM can save considerable energy and obtain higher throughput than low-energy adaptive clustering hierarchy (LEACH) and geographical adaptive fidelity (GAF).     

无线传感器网络中能量有效的波束成形机制

针对无线传感器网络中单个节点能量和通信距离均受限,以及传统波束成形机制中由于忽略能耗均衡而造成单个节点过早死亡的特点,提出了一种能量有效的波束成形机制。首先分析了节点个数、发射系数、功率受限、相位等因素对网络能耗的影响,给出了对应的设计原则。然后,基于此原则来选择参与发射的节点,并结合节点的剩余能量和相位来调整各自的发射系数。理论分析和仿真结果表明,该机制有效地增加了数据成功传输的次数,均衡了节点间的能耗,延长了网络寿命。     

SafeAnon: a safe location privacy scheme for vehicular networks

In most safety applications within vehicle ad-hoc networks (VANETs), vehicles need to periodically broadcast messages with information of their precise positions to others. These broadcast messages, however, make it easy to track vehicles and will likely lead to violations of personal privacy. Unfortunately, most of the current location privacy enhancement methodologies in VANETs suffer some shortcomings and do not take driving safety into consideration. In this paper, we propose a safe distance based location privacy scheme called SafeAnon, which can significantly enhance location privacy as well as traffic safety. By simulating vehicular mobility in a cropped Manhattan map, we evaluate the performance of the proposed scheme under various conditions. The mean entropy, warning broadcast ratio, and mean silent period of SafeAnon scheme are increasing 58%, 281%, and 50% respectively than the random silent period (RSP) scheme. The total broadcast ratio is also 33% less than that in the RSP scheme.     

A novel real-time scheme for (m,k)-firm streams in wireless sensor networks

The multimedia transmission based real-time applications have posed a big challenge to wireless sensor networks (WSNs) where both reliability and timeliness need to be guaranteed at the same time, to support an acceptable Quality of Service (QoS). The existing real-time routing protocols, however, are not able to meet the QoS requirements of realtime applications because of the inherent resource constraint of sensor nodes and instability of wireless communication. Therefore, we propose a real-time scheme in this paper, including a QoS-aware routing protocol and a set of fault recovery mechanisms, for (m,k)-firm based real-time applications over WSNs. A local status indicator which is specially devised for (m,k)-firm stream, is used for intermediate nodes to monitor and evaluate their local conditions. The proposed routing protocol takes into account of packet deadline, node condition and remaining energy of next hop, to make optimal forwarding decision. Additionally, according to the stream QoS and node condition, the proposed fault recovery mechanisms are utilized for nodes to handle the congestion, link failure and void problems occurred during transmission and remain the desired reliability and timeliness requirements. The proposed scheme has been well studied and verified through simulations. The results have proved the efficiency of the proposed scheme in terms of high successful transmission ratio, small end-to-end delay and long lifetime of network.     

A differential privacy protection scheme for sensitive big data in body sensor networks

As a special kind of application of wireless sensor networks, body sensor networks (BSNs) have broad application perspectives in health caring. Big data acquired from BSNs usually contain sensitive information, such as physical condition, location information, and so on, which is compulsory to be appropriately protected. However, previous methods overlooked the privacy protection issue, leading to privacy violation. In this paper, a differential privacy protection scheme for sensitive big data in BSNs is proposed. A tree structure is constructed to reduce errors and provide long range queries. Haar Wavelet transformation method is applied to convert histogram into a complete binary tree. At last, to verify the advantages of our scheme, several experiments are conducted to show the outperformed results. Experimental results demonstrate that the tree structure greatly reduces the calculation overheads which preserves differential privacy for users.