Location Verification Research Articles

An Approach for Location Verification using Atomic Localization in Wireless Sensor Networks

An Approach for Location Verification using Atomic Localization in Wireless Sensor Networks

Location verification algorithm of wearable sensors for wireless body area networks

Location verification algorithm of wearable sensors for wireless body area networks

Measurement of methane emissions from abandoned oil and gas wells in Hillman State Park, Pennsylvania

ABSTRACTAbandoned oil and gas wells, improperly plugged or unplugged, present a risk to current and future oil and gas development because they provide a potential pathway for unwanted gas and fluid migration to the surface. The appropriate emission factor for gaseous emissions from these wells is uncertain, as a limited number of studies have reported abandoned wells as a methane emissions source. A helicopter-based survey that mapped methane concentration and located wells by detecting magnetic anomalies was conducted in Hillman State Park in southwestern Pennsylvania. Although well finding via aerial survey was successful, elevated methane concentrations due to emissions from wells in the survey area were not detected by helicopter as abandoned wells were likely too small a source of methane to detect from elevations that helicopters fly at (tens of meters). Measurement of methane emission rates from 31 wells were collected using several techniques that are compared and evaluated for their effectiveness: Hi Flow sampler, field-portable flame ionization detector, infrared camera, dynamic flux chamber and bag sampling. Nine of the 31 wells were buried; average methane flux for these wells was not statistically different from the background. Mass flow rate from the remaining 22 wells ranged from non-detection (less than 0.09 kg CH4/day) to 4.18 kg CH4/day with a mean of 0.70 kg/well/day (median of 0.24 kg CH4/day/well) and a sample standard of error of 0.21 kg CH4/well/day. This emission factor, while not intended for exclusive use in developing a methane emissions inventory for abandoned oil and gas wells, contributes to the growing amount of methane emissions data for this source category. The results from the aerial survey, ground-based well location verification and emissions measurements, and the evaluation of measurement approaches described here, provide a comprehensive characterization of abandoned wells in one field that can inform future measurement studies.

Setup errors in radiation therapy for thoracic tumor patients of different body mass index.

PurposeTo assess the setup errors in radiation therapy for thoracic tumors patients of different somatotypes, and to seek an individualized mathematical basis for defining the planning target volume (PTV).MethodsSixty patients with thoracic tumors were divided into four somatotypes according to their body mass index (BMI), and their body positions were setup by two groups of technicians independently. CT simulations were performed and the reconstructed radiography was digitally generated as reference images for location verification and error measurement. By setting positioning error ranges, the within‐range positioning correction rate was compared among groups.ResultsPosition setups for patients in the emaciated group, moderate group, and overweight group were relatively stable (with minor setup error differences between the two groups of technicians). In emaciated group, moderate group, overweight group, and obese group, setup errors in the right–left direction (R‐L) were 2.2 ± 1.3 mm, 2.2 ± 1.6 mm, 3.9 ± 3.1 mm, and 8.8 ± 3.5 mm, respectively; whereas the setup errors in the four groups in the superior–inferior(S‐I) direction were 2.4 ± 1.8 mm, 2.1 ± 1.9 mm, 3.2 ± 2.6 mm, and 5.4 ± 3.5 mm, and in the anterior–posterior (A‐P) direction were 2.2 ± 1.7 mm, 1.9 ± 1.9 mm, 3.2 ± 2.9 mm, and 6.2 ± 4.2 mm, respectively. Moreover, in the moderate group, the positioning correction rate in the three directions (R‐L, S‐I, and A‐P) was 20%, 9%, 8% within the error range of 5–10 mm, and 3%, 0%, 1% with a more than 10 mm error range. However, in overweight group and obese group, the positioning correction rate in these three directions (also with a more than 10 mm error range) was 23%, 27%, 19% and 21%, 16%, 23%, respectively.ConclusionsIn radiation therapy for patients with thoracic tumors, the definition of PTV should be individualized. Meanwhile, with the increase in BMI, positioning correction rate has a tendency to rise too.

Location Verification Systems Based on Received Signal Strength With Unknown Transmit Power

In the context of location verification systems (LVSs), this letter proves that the knowledge of a legitimate user’s transmit power has no effect on the optimal performance of a received signal strength (RSS)-based LVS. Specifically, we prove that the detection performance of a generalized likelihood ratio test (GLRT), where the unknown transmit power is estimated, is identical to that of a differential likelihood ratio test (D-LRT). Our analysis also proves the asymptotic optimality of D-LRT for an RSS-based LVS with unknown transmit power. These results are important for real-world deployments of LVSs, since D-LRT incurs a significantly lower implementation cost relative to GLRT.

Multi Model Mitigation Approach for Network Threats on Cluster Based Linear Chain Routing Protocol in Wireless Sensor Networks at QoS Development

Consider the wireless sensor network (WSN) deployed in the motivation to perform data collection through the sensor nodes of the network deployed in different geographic region with same set of configuration where each can directly communicate to the base station. There are many routing protocols exists but the cluster based linear chain routing is focused towards reducing energy depletion by performing cooperative transmission to reach the destination. Because of the nodes has no mobility and the cluster formation is performed once, the linear chain routing protocol is more prone for variety of routing attacks which spoils the motivation of linear chain routing and reduce the lifetime of the network in rapid manner. We propose a multi model mitigation technique which handles variety of network threats happen in routing of packets increases the performance of WSN. This method performs flow estimation technique to identify the denial of service attacks and botnet based attacks. An light weight location verification protocol has been depicted to handle the sink hole attacks. The problem of packet dropping attack has been handled by one step verification process. The multi model mitigation techniques have produced efficient result in Quality of Service development and improve the performance of the linear chain routing.

Location Verification Assisted by a Moving Obstacle for Wireless Sensor Networks

With the rapid development of the Internet of Things, location information becomes increasingly important for various applications. However, the localization information of network devices is vulnerable to various attacks and not always trustworthy. In this paper, we propose a location verification scheme that allows the access point (AP) to verify credibility of a reported location from a network node with assistance of an obstacle that moves actively in the network at a random speed. When the obstacle blocks the transmissions between the AP and a network node, the received signal strength (RSS) at the node is reduced. For location verification, a network node is asked to report its location and the RSS for a period of time. Based on the changes in the reported RSS and the mobility information of the obstacle, the AP can determine whether the network node has reported the correct location. An analytical model is developed to find the performance of the proposed scheme. Simulation results show that the proposed scheme achieves high probability of detecting malicious nodes and low probability of treating legitimate nodes as malicious. Simulation results have also verified the accuracy of the analysis.

SLDS: Secure and location-sensitive data sharing scheme for cloud-assisted Cyber-Physical Systems

Cyber-Physical Systems (CPS) are engineered systems in which the computation, networking, physical processes and users are integrated seamlessly by the Internet. With the application of CPS technology in transportation, energy, manufacturing and other fields, the way people interact with engineered systems is significantly changed. Despite of plenty of benefits, CPS also suffers from many problems and the most important one is data security. On the one hand, the location of data is a link between the cyber space and the physical world. In some scenarios, the data is only allowed to be used in the desired areas, and thus the mobility of CPS devices introduces the location-related security requirements in data management. On the other hand, note that the monitors and sensor devices keep collecting and exchanging sensitive data all the time. As a result, it is a major security challenge for CPS to safely distribute massive amounts of data to the clients with limited resources. In this paper, we propose a new location verification protocol called Ears, which prevents both shortening and lengthening distance frauds in CPS environments. Besides, we design a secure location-sensitive data sharing (SLDS) scheme based on Ears, in which data access is controlled by identity as well as location and the shared data is re-encrypted after each retrieval. We can prove that the proposed Ears protocol and SLDS scheme can achieve the designed security properties. Furthermore, the experimental results show that our schemes are more efficient for real-world applications.

Phenylthiomethyl Ketone-Based Fragments Show Selective and Irreversible Inhibition of Enteroviral 3C Proteases.

Lead structure discovery mainly focuses on the identification of noncovalently binding ligands. Covalent linkage, however, is an essential binding mechanism for a multitude of successfully marketed drugs, although discovered by serendipity in most cases. We present a concept for the design of fragments covalently binding to proteases. Covalent linkage enables fragment binding unrelated to affinity to shallow protein binding sites and at the same time allows differentiated targeted hit verification and binding location verification through mass spectrometry. We describe a systematic and rational computational approach for the identification of covalently binding fragments from compound collections inhibiting enteroviral 3C protease, a target with high therapeutic potential. By implementing reactive groups potentially forming covalent bonds as a chemical feature in our 3D pharmacophore methodology, covalent binders were discovered by high-throughput virtual screening. We present careful experimental validation of the virtual hits using enzymatic assays and mass spectrometry unraveling a novel, previously unknown irreversible inhibition of the 3C protease by phenylthiomethyl ketone-based fragments. Subsequent synthetic optimization through fragment growing and reactivity analysis against catalytic and noncatalytic cysteines revealed specific irreversible 3C protease inhibition.

Image guidance improves gain ratio in radioactive seeds brachytherapy

Objective To investigate whether quality assurance and quality control using multimodal image guidance and radiation dosimetry optimization could ensure and improve the targeting of 125I seeds brachytherapy. Methods A total of 287 patients (184 males, 103 females, average age 61.9 years) with non-small-cell lung cancer (NSCLC) and 122 patients (average age 65.5 years) with prostate cancer who were diagnosed by pathology or imaging methods(coincidence imaging, CT, flexible fiberoptic bronchoscopy, ultrasonography) from October 2002 to October 2016 were retrospectively enrolled. All imaging methods were used to locate the target area. Optimization of radiation dosimetry was made according to treatment planning system (TPS) and evaluated by dose-volume histogram (DVH). 125I seeds implantation was performed under the imaging guidance, followed by real-time location verification, dosimetric verification. Therapeutic efficacy was evaluated. Paired t test was used to analyze the data. Results The prescribed dose (PD) of planning target volume (PTV) was above 140 Gy. Immediate dosimetric verification was performed in 59 patients with NSCLC and 31 patients with pulmonary metastases. The radiation dose before and after the implantation was coincident in 93.2%(55/59) of NSCLC and 93.5%(29/31) of pulmonary metastases. The coincident rate of patients with dose delivered to 90% GTV (D90)>matched peripheral dose (MPD) was 93.2%(55/59) and 87.1%(27/31) respectively in NSCLC and pulmonary metastases. There was no significant difference in MPD, D90 and conformity index (CI) before and after implantation (t values: 2.11-9.71, all P>0.05). The average dose of the risk organs was significantly lower than the tolerance dose of the normal tissue. The incidence of radiation pneumonitis was 1.05%(3/287). No other serious complications were found. Conclusion Targeted diagnosis and therapy of multimodal image guidance could be optimized to improve the effect of targeting and therapeutic gain ratio of 125I seeds brachytherapy. Key words: Carcinoma, non-small-cell lung; Radiotherapy, image-guided; Brachytherapy; Iodine radioisotopes

Server Location Verification (SLV) and Server Location Pinning

We introduce the first known mechanism providing realtime server location verification. Its uses include enhancing server authentication by enabling browsers to automatically interpret server location information. We describe the design of this new measurement-based technique, Server Location Verification (SLV), and evaluate it using PlanetLab. We explain how SLV is compatible with the increasing trends of geographically distributed content dissemination over the Internet, without causing any new interoperability conflicts. Additionally, we introduce the notion of (verifiable) server location pinning (conceptually similar to certificate pinning) to support SLV, and evaluate their combined impact using a server-authentication evaluation framework. The results affirm the addition of new security benefits to the existing TLS-based authentication mechanisms. We implement SLV through a location verification service, the simplest version of which requires no server-side changes. We also implement a simple browser extension that interacts seamlessly with the verification infrastructure to obtain realtime server location-verification results.

Location Verification of Wireless Internet Clients: Evaluation and Improvements

Client Presence Verification (CPV) was proposed in previous literature as a delay-based location verification algorithm that iteratively estimates Internet delays to corroborate assertions about a client’s geographic presence in a prescribed region, e.g., before granting access to a location-based service. We evaluate CPV’s performance in the presence of clients that use 802.11 networks by analyzing the following factors: the number of such clients in the network, how far adversaries are from their true locations, and the number of CPV iterations required to neutralize the effect of wireless networks. We use a mix of real-world traffic measurements from PlanetLab and existing wireless-delay probability models to create the evaluation datasets. The results indicate that, while wireless delays affect CPV’s performance (e.g., from 3 to $\sim$ 4.7 percent false reject/accept rates), CPV can mitigate the impact of such delays by performing more delay measurements prior to location verification. This work highlights the importance of including mitigation capabilities while designing security-sensitive applications and protocols to deal with the effect of wireless delays. This will become increasingly important with the ubiquitous use of mobile devices that is expected to increase with the introduction of new computing and communication paradigms such as the Internet of Things.

Drone Path Planning for Secure Positioning and Secure Position Verification

Many dependable systems rely on the integrity of the position of their components. In such systems, two key problems are secure localization and secure location verification of the components. Researchers proposed several solutions, which generally require expensive infrastructures of several fixed stations ( anchors ) with trusted positions. In this paper, we explore the approach of replacing all the fixed anchors with a single drone that flies through a sequence of waypoints. At each waypoint, the drone acts as an anchor and securely determines the positions. This approach completely eliminates the need for many expensive anchors. The main challenge becomes how to find a convenient path for the drone to do this for all the devices. The problem presents novel aspects, which make existing path planning algorithms unsuitable. We propose LocalizerBee , VerifierBee , and PreciseVerifierBee : three path planning algorithms that allow a drone to respectively measure, verify, and verify with a guaranteed precision a set of positions in a secure manner. They are able to securely localize all the positions in a generic deployment area, even in the presence of drone control errors. Moreover, they produce short path lengths and they run in a reasonable processing time.

Verifiable and Privacy-preserving Check-ins for Geo-social Networks

Enabling efficient and accurate location verification is a desirable technique for the proliferation of many “check-in” based location sharing services. Existing solutions either use modified infrastructures, such as WiFi APs and cellular towers, to issue location proofs for users, which suffer from high infrastructure extension cost, or rely on co-located users to issue location proofs for each other, which are vulnerable to collusion attacks. In this paper, we propose a novel location verification approach that is based on the concept of location tag. When a user requests to check-in at certain venue, both the device of the user and of the venue will submit a location tag, which actually is a collection of environmental signals presented at a certain location and time, to the service provider. Based on the similarity of the two location tags, the service provider can verify whether the user is actually at the location as she claimed. Due to the high time- and space- dependence of environmental signals, it is hard for users to forge location tags. On the other hand, to protect privacy of a user from the location-sharing service, periodically changed pseudonyms are used by users when checking-in at venues, and partially blind signatures are employed by the services to issue check-in confirmation messages. Then users will submit the check-in confirmation messages in a batch manner, using their true Identities. Thus, the location-sharing service knows who has checked-in at which venue, but does not know when the user did. As a result, temporal privacy of user check-ins can be achieved. Thorough analysis and experiments are conducted to demonstrate the feasibility, security and efficiency of the proposed approach.

The analysis of rock damage process based on the microseismic monitoring and numerical simulations

In mining process, the mechanical parameters of rock mass are deteriorating continuously. Fixed mechanical parameters were usually selected when using numerical simulation to analyze the damage process of rock mass, which led to the simulation results difficult to meet the actual situation. Microseismic monitoring system is an effective means to monitor the evolution of rock mass damage. It is of great significance to effectively combine the monitoring data with numerical simulation to correct rock mass parameters. In order to study the relationship between source parameters and rock mass damage, microseismic events of No. 15–16 exploratory line were analyzed from the project of Shirengou iron mine. Location verification was carried out on the established microseismic monitoring system and the microseismic events with larger errors were eliminated. The damage and failure characteristics of rock mass in this area were preliminarily analyzed based on the analysis of the temporal and spatial change of microseismic events and source parameters. In addition, based on the study of isotropic releasable strain energy, the damage model of rock mass was established by using the relationship between source parameters and releasable strain energy. The microseismic monitoring results were used as input of numerical simulation through FISH language existing in FLAC3D. Source parameters were used to modify rock mechanical parameters, so as to analyze the damage process of rock mass. Through the analysis of microseismic activity, the damage degree of rock mass and the change of plastic zone, the unstable areas were located, furthermore corresponding preventive measures were put forward.

Position based cryptography with location privacy: A step for Fog Computing

Fog Computing, which has the advantage of both the Cloud Computing and the Internet of Things, has changed our daily lives. One important property of the Fog Computing is location awareness. To guarantee this property in a practical hostile environment, location verification protocols are always desired. However, few location verification protocols can protect the location privacy of the location prover, who attempts to prove that he or she is at some position or in some region. Even worse, to the best of our knowledge, no location verification protocol has considered how to protect the location privacy against the verifiers of the protocol, who verify whether the prover is telling the truth.In this paper, we solve this problem by giving constructions of secure positioning protocol with location privacy in the bounded retrieval model. More precisely, we first explore how to define location privacy, which requires that nearly all parties except the prover, including verifiers and outside attackers, cannot learn any additional information about the exact position of the prover, for secure positioning protocol in the bounded retrieval model. Then we illustrate how to construct protocols satisfying this definition. In particular, we present a construction in the one-dimension setting, which explains the basic idea of our construction, and a construction in the three-dimensions setting, which can capture most practical scenarios. Amazingly, privacy is achieved without introducing additional computation overhead, and our system is as efficient as the one constructed in Chandran et al. (CRYPTO 2009). Besides, based on our proposed secure positioning protocols with location privacy, we also build more advanced cryptographic protocols exploiting location verification, e.g., position based key exchange, position based multi-party computation, position based public key infrastructure, etc., all of which still preserve the location privacy. Finally, we also give a proof of concept implementation of our system, which demonstrates that our system is quite practical in practice.

白江戰鬪의 位置 확인에 대한 接近

白江戰鬪의 位置 확인에 대한 接近

CPV: Delay-Based Location Verification for the Internet

The number of location-aware services over the Internet continues growing. Some of these require the client’s geographic location for security-sensitive applications. Examples include location-aware authentication, location-aware access policies, fraud prevention, complying with media licensing, and regulating online gambling/voting. An adversary can evade existing geolocation techniques, e.g., by faking GPS coordinates or employing a non-local IP address through proxy and virtual private networks. We devise Client Presence Verification (CPV), a delay-based verification technique designed to verify an assertion about a device’s presence inside a prescribed geographic region. CPV does not identify devices by their IP addresses. Rather, the device’s location is corroborated in a novel way by leveraging geometric properties of triangles, which prevents an adversary from manipulating measured delays. To achieve high accuracy, CPV mitigates Internet path asymmetry using a novel method to deduce one-way application-layer delays to/from the client’s participating device, and mines these delays for evidence supporting/refuting the asserted location. We evaluate CPV through detailed experiments on PlanetLab, exploring various factors that affect its efficacy, including the granularity of the verified location, and the verification time. Results highlight the potential of CPV for practical adoption.

An Efficient Location Verification Scheme for Static Wireless Sensor Networks.

In wireless sensor networks (WSNs), the accuracy of location information is vital to support many interesting applications. Unfortunately, sensors have difficulty in estimating their location when malicious sensors attack the location estimation process. Even though secure localization schemes have been proposed to protect location estimation process from attacks, they are not enough to eliminate the wrong location estimations in some situations. The location verification can be the solution to the situations or be the second-line defense. The problem of most of the location verifications is the explicit involvement of many sensors in the verification process and requirements, such as special hardware, a dedicated verifier and the trusted third party, which causes more communication and computation overhead. In this paper, we propose an efficient location verification scheme for static WSN called mutually-shared region-based location verification (MSRLV), which reduces those overheads by utilizing the implicit involvement of sensors and eliminating several requirements. In order to achieve this, we use the mutually-shared region between location claimant and verifier for the location verification. The analysis shows that MSRLV reduces communication overhead by 77% and computation overhead by 92% on average, when compared with the other location verification schemes, in a single sensor verification. In addition, simulation results for the verification of the whole network show that MSRLV can detect the malicious sensors by over 90% when sensors in the network have five or more neighbors.

Primary user Emulation Attack Defense in Filter Bank based Cognitive Radio

Background/Objectives: The spectrum scarcity problem arising due to reckless development in wireless communication can be addressed using cognitive radio technology. An important step in cognitive radio technology is spectrum sensing and associated with that is an attack called primary user emulation attack. Methods/Statistical Analysis: A two channel Quadrature Mirror Filter (QMF) bank is employed for a single user spectrum sensing. The energy detection method is used as reference for comparing the performance of the filter bank method in the presence of attackers. Existing approaches like Neyman-Pearson Criterion, Improved Detection Scheme with Double threshold and Location Verification Method for detecting PUE attacks were examined. A new method which combines improved detection scheme and location verification method is proposed for detecting PUE attacks. Findings: The simulation result shows that the filter bank method shows better performance than the energy detection method in the presence of attackers. The probability of detection of PUE attacks using improved detection scheme and location verification method for the filter bank method and energy detection method was analyzed and found out that the filter bank based spectrum sensing method outperforms energy detection method. By incorporating AND rule logic, OR rule logic and Alternate logic approach into the filter bank spectrum sensing technique, the probability of detection of PUE attack was investigated and it is seen that the probability of detection has increased to 0.98 in FB method at SNR = 1 dB when employing an alternate approach. Application/Improvements: The feasibility of deploying the filter bank method integrated with the alternate logic is to be tested using Universal Software Radio Peripheral (USRP) module.