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RFID is one of the most prominent identification schemes in the field of pervasive systems. Nonline of sight capability makes RFID systems much better choice than its contended systems (such as barcode, magnetic tape, etc.). Since the RFID uses wireless channel for communication with its associated devices, there should be some optimal encryption methods to secure the communicating data from adversaries. Several researchers have proposed ultralightweight mutual authentication protocols (UMAPs) to secure the RFID systems in cost effective manner. Unfortunately most of the previously proposed UMAPs are later found to be vulnerable against various desynchronization, Denial of Service (DoS), traceability, and full disclosure attacks. In this paper, we present a more sophisticated UMAP to provide Strong Authentication and Strong Integrity (SASI) using recursive hash function. The proposed protocol incorporates only simple bitwise logical operators XOR, Rot, and nontriangular function (recursive hash) in its design, which can be efficiently implemented with a low cost passive RFID tag. The performance analysis of the protocol proves the conformation of the proposed protocol with EPC-C1G2 passive tags. In addition to privacy and security, small chip area (miniaturization) is another design constraint (which is mandatory requirement for a protocol to be considered as ultralightweight authentication protocol). We have also proposed and implemented the efficient hardware design of the proposed protocol for EPC-C1G2 tags. Both the FPGA and ASIC implementation flows have been adopted. The FPGA flow is primarily used to validate the functionality of the proposed hardware design whereas ASIC flow (using TSMC 0.35 μm library) is used to validate the gate count. To the best of our knowledge, this is the first FPGA and ASIC implementation of any ultralightweight RFID authentication protocol. [ABSTRACT FROM AUTHOR]

Wireless technology will be widely used in libraries with the development of the mobile network in the near future. This paper focuses on MAC protocol for wireless network based on ultra-wideband band (UWB) to solve the problems of real-time and reliability in the wireless transmitting. According to the particular signal characteristics such as low energy consumption and excellent location, we propose a multichannel MAC protocol (UWBIMAC) based on status-adaptive to choose the channel mechanism. Simulation results show that the protocol had the ability of stronger antijamming, improved network throughput, and provided better average delay performance than IEEE802.15.4 MAC, IEEE802.11 MAC, and other UWBIMAC protocols. This method could be used in the process of wireless transmission service in the library or other similar scenarios. To a certain extent, it solves the problem of real-time and reliable performance in the process of wireless communication. [ABSTRACT FROM AUTHOR]

Wireless sensor networks (WSNs) are a family of wireless networks that usually operate with irreplaceable batteries. The energy sources limitation raises the need for designing specific protocols to prolong the operational lifetime of such networks. These protocols are responsible for messages exchanging through the wireless communications medium from the sensors to the base station (sink node). Therefore, the determination of the optimal location of the sink node becomes crucial to assure both the prolongation of the network’s operation and the quality of the provided services. This paper proposes a novel algorithm based on a Particle Swarm Optimization (PSO) approach for designing an energy-aware topology control protocol. The deliverable of the algorithm is the optimal sink node location within a deployment area. The proposed objective function is based on a number of topology control protocol’s characteristics such as numbers of neighbors per node, the nodes’ residual energy, and how they are far from the center of the deployment area. The simulation results show that the proposed algorithm reveals significant effectiveness to both topology construction and maintenance phases of a topology control protocol in terms of the number of active nodes, the topology construction time, the number of topology reconstructions, and the operational network’s lifetime. [ABSTRACT FROM AUTHOR]

With the rapid development in wireless communications and cloud computing technologies, clients (users) often use handheld mobile devices to access remote servers via open network channels. To provide authentication and confidentiality between clients and servers, a large number of ID-based authentication and key exchange (ID-AKE) protocols have been proposed for mobile client-server environments. However, most of the existing ID-AKE protocols adopt the precomputation technique so that they become vulnerable to the ephemeral-secret-leakage (ESL) attacks, in the sense that an adversary could use the ephemeral secrets to reveal the private keys of clients from the corresponding exchange messages. In the paper, we propose a new ESL-secure ID-AKE protocol for mobile client-server environments. We formally prove that the proposed protocol satisfies the security requirements of both mutual authentication and key exchange while resisting the ESL attacks. When compared with previously proposed ID-AKE protocols, our protocol has higher security and retains computational performance, since it requires no bilinear pairing operation for mobile clients. Finally, we mention the possibility of adopting our protocol as an authentication method of the extensible authentication protocol (EAP) for wireless networks. [ABSTRACT FROM AUTHOR]

Communication and information technologies play crucial roles in the smart grid system. Wireless communications offer many unique features to utilities. Real-time capability and high efficiency under heavy load are vital capabilities for smart grid wireless communications. However, the existing medium access control (MAC) protocols for low-rate and short-range wireless transfer in the literature mainly aim to achieve the objectives of low energy consumption and self-configuration and rarely address these requirements under heavy traffic intensity. This paper presents a real-time, efficient, and lightweight MAC (RE-MAC) protocol to support smart grid applications, based on priority node polling and a hybrid scheme. The upper bounds of packet delay are determined using the embedded Markov chain method, and the simulation results demonstrate that the protocol can achieve predictable, real-time, and efficient performance. [ABSTRACT FROM AUTHOR]

With the explosive growth and wide-spread use of smartphones with Wi-Fi enabled, people are used to accessing the internet through Wi-Fi network interfaces of smartphones. Smartphones periodically transmit Wi-Fi messages, even when not connected to a network. In this paper, we describe the Mo-Fi system which monitors and aggregates large numbers of continuous Wi-Fi message transmissions from nearby smartphones in the area of interest using nonintrusive Wi-Fi sniffer sensors. In this paper, we propose an optimized Wi-Fi channel detection and selection method to switch the best channels automatically to aggregate the Wi-Fi messages based on channel data transmission weights and human presence activity classification method based on the features of human dwell duration sequences in order to evaluate the user engagement index. By deploying in the real-world office environment, we found that the performance of Wi-Fi messages aggregation of CAOCA and CACFA algorithms is over 3.8 times higher than the worst channel of FCA algorithms and about 76% of the best channel of FCA algorithms, and the human presence detection rate reached 87.4%. [ABSTRACT FROM AUTHOR]

In wireless sensor networks (WSN), Sybil attack can destroy the routing and data distributed storage mechanisms through fabricating identity information of legitimate nodes. This paper presents a chain key predistribution based approach against Sybil attack. To enhance the security of common keys between neighboring nodes, during the chain key predistribution phase, our approach uses a lightweight hash function to generate several chain keys by hashing the unique identity information of every node sequentially in the trusted base station. These chain keys construct a pool of chain keys. During the pairwise key authentication establishment phase, a node-to-node chain key based authentication and exchange (CK-AE) protocol is proposed, by which each node can share the unique pairwise key with its neighboring node. The CK-AE protocol is provably secure in the universally composable security model (UCSM). Finally, we analyze our approach from the resilience of network and the performance overhead, and the results show that our approach can not only enhance the ability of resilience to Sybil attack, but also reduce the communication overhead significantly at the cost of a certain amount of computational overhead. [ABSTRACT FROM AUTHOR]

The vehicular mobility is reflection and extension of the human social activity. Since human trajectories show a high degree of temporal and spatial regularity, thus vehicular driving paths are predictable to a large extent. In this paper, we firstly analyze the predictabilities of different types of vehicles and then propose a new driving path predication based routing protocol (DPPR). With hello messages to broadcast vehicles' driving path predication information to neighbor vehicles, DPPR can observably increase the successful ratio to find the proper next hop vehicles that move toward the optimal expected road in intersection areas. In roads with sparse vehicle density, DPPR utilizes vehicles to carry messages to roads with high vehicle density while the messages' forward paths partially coincide with the vehicles' driving paths. Moreover, as to messages that can tolerate long delay, they can be carried to destinations by vehicles whose driving paths will pass the messages' destination in order to optimize bandwidth utilization. Simulation results demonstrate the effectiveness of the proposed DPPR protocol. [ABSTRACT FROM AUTHOR]

Intervehicle communication gives vehicles opportunities to exchange packets within the limited radio range and self-organized in Ad Hoc manner into VANETs (Vehicular Ad Hoc Networks). However, due to issues such as the high mobility, insufficient market penetration ratio, and lacking of roadside units, connectivity is actually a big problem in VANETs. In addition, relying only on the direct connectivity in most of the previous works, say broadcasting which provides one-hop connections between nodes is far from the continuously growing application demands in VANETs, such as inter-vehicle entertainments, cooperative collision avoidances, and inter-vehicle emergency notifications. Therefore, the indirect connectivity from multihop forwarding is also a necessary complement especially for the case where direct connection is hardly achieved. In this paper, we define a new metric, that is, available connectivity, to consider both direct and indirect connectivity. After analyzing the statistical properties of direct and indirect connectivity in vehicular environment, the available connectivity is proposed and quantified for practical usage. Numerical results show that our available connectivity could provide correct and useful references for protocols design and performance improvements of different applications. [ABSTRACT FROM AUTHOR]

Due to the potentials in promoting the driving safety and easing the traffic congestion, vehicular networks, especially vehicle-to-vehicle (V2V) communications, have recently been receiving much attention. The data dissemination protocol for V2V applications should not only provide end-to-end transmissions with low error probability and high throughput but also offer antieavesdropping capabilities. To achieve this goal, we in this paper propose a secrecy-enhanced relaying protocol for vehicular environments. Based on the network topology and the velocity of the moving vehicles, the proposed scheme first generates the relay candidate set, from which a single relay is then selected opportunistically to assist the source. By using the superposition coding strategy, the selected relay jointly sends the source message and the artificial interference to enable secure communications. We derive the tight closed-form expressions for the upper and lower bounds of the secrecy outage probability, based on which we analyze the diversity order of the system. The method to generate the interference signal is introduced, and the choice of superposition weight factor is also given. The analytical and simulation results show that the proposed relay-aided protocol yields a better performance than the competing alternatives in terms of both the secrecy performance and the implementation complexity. [ABSTRACT FROM AUTHOR]

Data broadcast is a fundamental operation in wireless sensor networks (WSNs). The existence of wireless interference makes it nontrivial to design a minimum-latency broadcast scheme, which is known to be NP-hard. Existing works all assume strict time synchronization and provide centralized TDMA scheduling algorithms. However, WSNs in practice are more likely to be distributed asynchronous systems. In this paper, we investigate the problem of data broadcast with minimum latency for distributed asynchronous WSNs. To this end, we propose a Distributed Asynchronous Broadcast (DAB) algorithm which crucially leverages an elaborately optimized carrier-sensing range together with collision-backoff schemes to coordinate the transmissions among the nodes on a predetermined broadcast backbone. Theoretical analysis shows that DAB is order-optimal and achieves constant factor approximation to the optimal delay. We then conduct extensive simulations to evaluate the practical capability of DAB in asynchronous WSNs and the results corroborate our theoretical analysis. [ABSTRACT FROM AUTHOR]

Mobile ad hoc networks (MANETs) are formed by wireless mobile devices that do not require a predefined infrastructure and where all nodes are at the same level without the need of a central coordinator. The routing is an important task in this kind of networks because of highly dynamic environments and other characteristics. Routing consists of sending the information from sender nodes to destination nodes in a multihop manner. There are different techniques to solve the routing problem. We rely on bioinspired algorithms, those that take into account the behavior of certain animals to solve it. Specifically we design a novel routing algorithm based on Ant Colony Optimization (ACO) which uses the concepts of Swarm Intelligence and analyzes the behavior of ants at the time of obtaining the food. In this work, we present Hybrid ACO Routing (HACOR), a bio-inspired protocol based on ACO. In the simulation results, we observe how this protocol performs significantly better compared to a state-of-the-art routing protocol, according to the analyzed metrics. [ABSTRACT FROM AUTHOR]

In wireless sensor network, when these sensors are wrongly placed in an observation region, they can quickly run out of batteries or be disconnected. These incidents may result in huge losses in terms of sensing data from numerous sensors and their costs. For this reason, a number of simulators have been developed as tools for effective design and verification before the actual arrangement of sensors. While a number of simulators have been developed, simulation results can be fairly limited and the execution speed can be markedly slow depending on the function of each simulator. In this regard, to improve the performance of existing simulators, this research aimed to develop a parallel calculation simulator for independent sensor (PCSIS) that enables users to selectively use the GPU mode and, based on this mode, enables parallel and independent operations by matching GPU with many cores in order to resolve the slowdown of the execution speed when numerous sensor nodes are used for simulations. The PCSIS supports the GPU mode in an environment that allows the operation of compute unified device architecture (CUDA) and performs the parallel simulation calculation of multiple sensors using the mode within a short period of time. [ABSTRACT FROM AUTHOR]

We present in this paper an investigation of a special class of wireless sensor networks for monitoring critical infrastructures that may extend for hundreds of miles in distances. Such networks are fundamentally different from traditional sensor networks in that the sensor nodes in this class of networks are deployed along narrowly elongated geographical areas and form a chain-type topology. Based on careful analysis of existing sensor network architectures, we first demonstrate the need to develop new architecture and networking protocols to match the unique topology of chain-type sensor networks. We then propose hierarchical network architecture that consists of clusters of sensor nodes to enable the chain-type sensor networks to be scalable to cover typically long range infrastructures with tolerable delay in network-wide data collection. To maintain energy efficient operations and maximize the lifetime for such a chain-type sensor network, we devise a smart strategy for the deployment of cluster heads. Protocols for network initialization and seamless operations of the chain-type sensor networks are also developed to match the proposed hierarchical architecture and cluster head deployment strategy. Simulations have been carried out to verify the performance of the hierarchical architecture, the smart node deployment strategy, and the corresponding network initialization and operation protocols. [ABSTRACT FROM AUTHOR]

Volunteer forwarding, as an emerging routing idea for large scale, location-aware wireless sensor networks, has recently received significant attention. However, several critical research issues raised by volunteer forwarding, including communication collisions, communication voids, and time-critical routing, have not been well addressed by the existing work. In this paper, we propose a priority-based stateless geo-routing (PSGR) protocol that addresses these issues. Based on PSGR, sensor nodes are able to locally determine their priority to serve as the next relay node using dynamically estimated network density. This effectively suppresses potential communication collisions without prolonging routing delays. PSGR also overcomes the communication void problem using two alternative stateless schemes, rebroadcast and bypass. Meanwhile, PSGR supports routing of time-critical packets with different deadline requirements at no extra communication cost. Additionally, we analyze the energy consumption and the delivery rate of PSGR as functions of the transmission range. Finally, an extensive performance evaluation has been conducted to compare PSGR with competing protocols, including GeRaf, IGF, GPSR, flooding, and MSPEED. Simulation results show that PSGR exhibits superior performance in terms of energy consumption, routing latency, and delivery rate, and soundly outperforms all of the compared protocols. [ABSTRACT FROM AUTHOR]

For enhancing the security of ubiquitous communication, we have to consider three keywords: mobility, wireless, and low computing capability. In this paper, we study one of suitable security protocols for the ubiquitous communication environment. We discuss RSA-based password-authenticated key exchange (RSA-PAKE) protocols for imbalanced wireless networks where a party uses a low-power device to communicate with another party equipped with a powerful computing device. For imbalanced wireless network applications, it is important to reduce the cost of communication for a low-power device even though the cost for powerful devices is increasing. The most power-consuming operation in RSA-PAKE protocols is the reliability test of unauthorized RSA public keys. Hence, it is important to design an efficient reliability test method to construct an efficient RSA-PAKE protocol. In this paper, we propose a new reliability test technique and design a provably secure RSA-PAKE protocol using the technique. Our protocol is suitable for securing the communications conducted over imbalanced wireless networks since the operations computed by one communicating party are efficient enough to be implemented on most low-power devices such as mobile phones and PDAs. The cost of a low-power device is reduced by 84.25% compared with CEKEP, the most efficient RSA-PAKE protocol. We prove the security of our protocol under a firmly formalized security model. [ABSTRACT FROM AUTHOR]