Enhanced source location privacy and prolonged network lifetime are imperative for WSNs-the skin of IoT. To address these issues, a novel technique named source location privacy with enhanced privacy ...and network lifetime (SLP-E) is proposed. It employs a reverse random walk followed by a walk on annular rings, to create divergent routing paths in the network, and finally, min-hop routing together with the walk on dynamic rings to send the packets to the base station (BS). The existing random walk-based SLP approaches have either focused on enhancing only privacy at the cost of network lifetime (NLT) or have aimed at improving the amount of privacy without degrading the network lifetime performance. Unlike these schemes, the objectives of the proposed work are to simultaneously improve the safety period and network lifetime along with achieving uniform privacy. This combination of improvements has not been considered so far in a single SLP random walk-based scheme. Additionally, this study investigates for the first time the impact of the sensors' radio range on both privacy strength and network lifetime metrics in the context of SLP within WSNs. The performance measurements conducted using the proposed analytical models and the simulation results indicate an improvement in the safety period and network lifespan. The safety period in SLP-E increased by 26.5%, 97%, 123%, and 15.7% when compared with SLP-R, SRR, PRLPRW, and PSSLP techniques, respectively. Similarly, the network lifetime of SLP-E increased by 17.36%, 0.2%, 83.41%, and 13.42% when compared with SLP-R, SRR, PRLPRW, and PSSLP techniques, respectively. No matter where a source node is located within a network, the SLP-E provides uniform and improved privacy and network lifetime. Further, the simulation results demonstrate that the sensors' radio range has an impact on the safety period, capture ratio, and the network lifetime.
In wireless sensor networks (WSNs), the existing cluster-based private data aggregation techniques are energy-intensive due to high message transmission complexity. Reliable data transmissions are ...also vital for resource constraint WSNs. To address these issues, the authors propose a reliability enabled private data aggregation technique that has message transmission complexity of ${\cal O}\lpar N\rpar $O(N). Every node in the cluster cleaves its data into n integrants using simple modular arithmetic with suitable prime moduli and transmits to the cluster heads (CHs) for intermediate aggregation. The CHs, in turn, forward the partial aggregate data to the base station where the final aggregate is recovered using an elegant Chinese remainder theorem. The authors use data privacy, communication overhead, and reliability metrics to gauge the performance of the proposed work. Numerical and simulation results demonstrate that the proposed solution outperforms the existing schemes having ${\cal O}\lpar N^2\rpar $O(N2) communication complexity.
Privacy of critical locations (or events) is essential when monitored by wireless sensor networks. To mitigate such issues, in this article, a new privacy protection technique named ...position-independent and section-based source location privacy (PSSLP) is developed. A biased random walk and greedy walk using a three- or four-phase routing strategy is employed here, where the number of phases depends on the network segment in which the source is situated. The biased random walk is intended to send packets away from the source of information and make routing paths appear dynamic to the eavesdropper, whereas, the greedy routing ensures that the packets converge at the base station. The objective of the solution is to achieve a uniform amount of privacy irrespective of the position of the asset in the network without compromising the network lifetime. Performance evaluation is done using developed analytical models and simulation results reveal that PSSLP achieves 8247.06- and 33.0- folds improvement in terms safety period and network lifetime, respectively, compared to no SLP protection technique (i.e., shortest path routing technique).
Remote monitoring in wireless sensor networks (WSNs) requires enhanced privacy and long-term monitoring of objects or events without escalating delay. To address this problem, a strategic random walk ...routing for protecting source location privacy (SRWSLP) in wireless sensor networks (WSNs) is proposed in this article. The proposed technique routes the packets from the source node to the base station (BS) using three phases of routing, namely: i) adaptive backward random walk (A-BRW), ii) adaptive equal depth routing (A-EDR), and iii) forward random walk (FRW). In order to give an impression to a backtracking attacker that the routing pathways are dynamic, the A-BRW and A-EDR phases are designed to carefully route the packets away from the source node in the first two phases of routing. In the third phase, the packets are sent to the base station (BS) using the forward random walk. The objective of the solution is to achieve improved privacy and network lifetime without affecting delay. Simulation results have demonstrated that the proposed technique performs better than the existing random walk class of SLP techniques.
In this paper, we propose a two-phase routing technique using multiple virtual sources to provide enhanced source location privacy in Wireless Sensor Networks (WSNs). We use the concept of ...escape-angle and random walks that is based on potential energy. The proposed method routes packets to the base station via different virtual sources located at various positions in the network. The key idea of this work is to exploit the excess energy available in the non-hotspot areas of the network to generate dispersive routes between source node and the virtual sources. This approach maximizes safety-period without hampering the network lifetime. We present mathematical models to estimate the overall energy expenditure that incurs at each node during Min Hop Routing phase (phase two). We then determine the remaining amount of energy which could be used for Stochastic and Diffusive Routing phase (phase one). Simulation results show that the proposed technique achieves improved safety-period without hampering the network lifetime.
A major limitation to the use of wireless sensor networks (WSNs) in asset monitoring applications is security and privacy, particularly the privacy of source location information. In this article, we ...develop two phantom routing-based solutions to provide source location privacy for the case of multisource/asset scenario-the case that has received very little attention in the literature. The idea of phantom routing is to relay the packets to a distant node in a random fashion to obfuscate the traffic flows and confuse the attacker. The first technique phantom routing-based backward random walk (PRBRW) uses a combination of backward random walk (RW) and a greedy forwarding approach to route the packets to the base station (BS). Although the first approach has better performance improvements in terms of capture ratio and safety period it hampers the lifetime of the network and has a poor entropy metric. To better this problem, an improved phantom routing scheme phantom routing-based L-path RW (PRLPRW) is proposed. The second technique has three phases: 1) pure RW; 2) L-walk; and 3) greedy walk. This technique performs well in terms of capture ratio, safety period, and entropy metrics. The improvement in network lifetime is 10-folds and entropy is 477-folds when compared with PRBRW. The performance is evaluated using the developed analytical models and compared with the baseline protection-less scheme shortest path routing (SPR). It is observed that PRBRW and PRLPRW, respectively, have 60- and 73-fold improvements in terms of capture ratio when compared with SPR, whereas existing phantom routing-based pure RW and forward RW techniques, respectively, have only 54- and 34-fold improvements.
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•Tetragonal phase of Bismuth oxychloride (BiOCl) nanoparticles was successfully prepared via co-precipitation method at room temperature method.•Characterization of BiOCl NPs were ...characterized by XRD, UV-DRS, Raman, SEM and TEM techniques.•BiOCl NPs exhibit critical non-toxic properties on human erythrocytes as well as interference in the activity coagulation cascade on both PRP and PPP in human blood.•The determining the MIC and MBC of BiOCl NPs demonstrated significant inhibitory activity against pathogenic bacterial strains S.aureus and P. aeruginosa.
Bismuth oxychloride (BiOCl) nanoparticles was successfully prepared via co-precipitation method at room temperature method. The structural, optical and morphological features of BiOCl NPs were characterized by XRD, UV-DRS, Raman, SEM and TEM techniques. The XRD pattern of BiOCl NPs shows tetragonal phase with an average crystalline size was found to be 23 nm. The energy band gap of BiOCl NPs is 3.5 eV with the help of UV-DRS. Raman spectroscopy was used to identify the characteristic A1g and Eg vibrational normal modes of BiOCl NPs. SEM and TEM micrographs of BiOCl NPs reveals the agglomeration of the particles with effect of reducing agent. Furthermore, MIC and MBC of BiOCl NPs demonstrated significant inhibitory activity against pathogenic bacterial strains S.aureus and P.aeruginosa. BiOCl NPs exhibit critical non-toxic properties on human erythrocytes as well as interference in the activity coagulation cascade on both PRP and PPP in human blood. As a result, the study reveals that the synthesis of BiOCl nanoparticles is very simple, inexpensive, and environmentally friendly, and that it has the potential to discover novel properties of biological activities.
Photocatalytic performance of precursor solution-aged undoped, Zn-doped CdO (CdO:Zn) and Ag-doped CdO (CdO:Ag) thin films has been reported in this paper. Perfume atomizer is adopted to deposit the ...films. CdO, CdO:Zn and CdO:Ag thin films exhibit cubic crystal structure. The crystallite size values were 34, 31 and 27 nm, respectively, for the CdO, CdO:Zn and CdO:Ag thin films. In the EDX spectra of the CdO:Zn and CdO:Ag thin films, Zn and Ag were observed along with Cd and O. The CdO:Zn and CdO:Ag thin films exhibit increased transparency and widened band gap values. PL spectra showed peaks related to oxygen vacancies for all the films. Reduced resistivity was evinced for the CdO:Zn and CdO:Ag thin films. The degradation efficiencies of the CdO, CdO:Zn and CdO:Ag thin films against methyl orange after 75 min light exposure were 76.4, 84.3 and 90.4%, respectively. The CdO:Zn and CdO:Ag catalysts exhibit satisfactory stability with better reusable nature and are suitable for the effective treatment of organic toxic dyes.
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