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关键词： computer network security   cryptographic protocols   message authentication   radio frequency identification  

摘要： In present times, Radio-Frequency Identification (RFID) systems have seen a significant rise in their usage. There has been an increasing interest in developing even lighter RFID protocols suitable for resource-constrained environments. Ensuring security and privacy remain critical challenges in RFID-based systems. Recently proposed lightweight authentication schemes, namely LRSAS+ and LRARP+, are ideally suited for constrained devices. However, this article investigates these schemes and reveals certain vulnerabilities: LRSAS+ is susceptible to tag impersonation, desynchronization, and traceability attacks, while LRARP+ can fall prey to traceability and secret disclosure attacks. An enhanced version of these authentication systems is proposed that tackles their inherent weaknesses by leveraging the chi per$\chi per$ function. To verify the security of the proposed scheme, a formal analysis is conducted using Gong-Needham-Yahalom logic (GNY logic) and an automated security protocol verification tool, ProVerif. The improved scheme's effectiveness is also compared with multiple contemporary lightweight systems. The results indicate that the enhanced scheme not only meets the security requirements for lightweight authentication schemes but also achieves this with minimal computational overhead. Our article investigates the vulnerabilities of lightweight RFID authentication schemes, namely LRSAS+ and LRARP+, and proposes an enhanced version leveraging the chi per$\chi per$ function to address their weaknesses. Through formal analysis and comparison with contemporary systems, we demonstrate that the improved scheme achieves robust security while minimizing computational overhead, making it suitable for resource-constrained environments. image

关键词： Wearable antenna   Circular polarization   Global positioning system (GPS)   Radio frequency identification (RFID)   Specific absorption rate (SAR) analysis  

摘要： A dual funtional dual patch wearable antenna integrated into a military beret, is developed for indoor and outdoor positioning system. The composite antenna consists of an inner double-slit circular patch with an outer square ring patch with four conductive thread vias. The inner patch is designed for global positioning systems, operating in the L1 band (1.563-1.587 GHz), for outdoor applications. The slits are made orthogonal to each other, for exciting two orthogonal modes needed for achieving circular polarization by degenerating the fundamental TM11 mode. The outer square ring patch generating monopole-type radiation pattern, is designed for radio frequency identification in the ISM band (902-928 MHz), for indoor applications. It resonates at a higher-order mode of TM41 at 915 MHz, caused by the integration of the fields developed by suitable positioning of four conductive thread vias. They split the surface current distribution into 4 half-cycles, leading to the generation of the TM41 mode. The antenna is realized and fabricated using felt as substrate and conductive metalized nylon fabric for patch and ground plane of the composite antenna. The bending effects of the wearable antenna over the standard human head phantom is also analyzed by comparing simulated and measured results. A comprehensive specific absorption rate analysis over a typical human head (six-layered) phantom is carried out to evaluate the radiation effects. Comparative analysis with pre-published antenna systems operating in similar frequency bands has been studied, indicating that the proposed antenna system outperforms them.

关键词： extended gradient filter (EGF)   quantum neural network (QNN)   radio frequency identification (RFID)   RFID reader   virtual reference tag allocation  

摘要： In an indoor setting, the radio frequency communication is utilized to locate and track mobile objects utilizing Radio Frequency Identification (RFID) technology. Measurements from the Received Signal Strength Indicator (RSSI) are typically the foundation of the localization technique. In an RFID-based interior setting, lowering tracking mistakes and increasing the precision of tracking remain difficult tasks. In order to address these issues, we developed the VIRALTRACK (Virtual Reference Tag Localization and Tracking) framework that consists of four procedures: deep reinforced learning-based tracking, quantum-based localization, optimization-based virtual reference tag allocation, and signal enhancement. In order to increase the signal's effectiveness, we initially suggested using the Extended Gradient Filter (EGF) technique to eliminate RSSI oscillations. In the second step, we suggested using the Emperor Penguin Colony (EPC) optimization technique to allocate the virtual reference tag while taking the number of tags, SNR, and temperature and humidity of the surroundings into account. In the third phase, we use a quantum neural network (QNN) for localization in order to estimate the position of the moving target. We introduced the SignRank approach to select the best virtual reference tag for localization, which lowers tracking mistakes. In conclusion, we presented the Twin Delayed Deep Deterministic Policy Gradient (TD3) method that boosts the tracking precision by tracking the moving target tag efficiently and taking into account stage, the orientation, distance, and valuable coordinates. The NS3.26 network simulator is used to run the simulation, and tracking precision, tracking error, and accumulated probabilities are used to assess effectiveness. The distribution of virtual reference tags according to optimization algorithms lessens disturbance brought on by the tracking system's greater utilization of real reference tags. The geographic distribution of movi

关键词： Robots   Location awareness   Radiofrequency identification   Antennas   Hardware   Three-dimensional displays   Mobile robots   RFID-robot   localization   speed inconsistency  

摘要： A wide range of scenarios, such as warehousing, and smart manufacturing, have used RFID mobile robots for the localization of tagged objects. The state-of-the-art RFID-robot based localization works are based on the premise of stable speed. However, in reality this assumption can hardly be guaranteed because Commercial-Off-The-Shelf (COTS) robots typically have inconsistent moving speeds, and a small speed inconsistency will cause a large localization error. To this end, we propose a Speed Inconsistency-Immune approach to mobile RFID robot Localization (SILoc) system, which accurately locates targets when the robot moving speed varies or is even unknown. We propose an optimized unwrapping method to maximize the use of data, and a lightweight algorithm to calculate the locations in both 2D and 3D spaces. By utilizing the characteristics of tag-antenna distance and combining the phase data from multiple antennas, SILoc can effectively eliminate the side effects of speed inconsistency. To increase the flexibility, we further optimize the system and propose SILoc+, which enables the system to achieve localization with part of the data, keeping speed inconsistency-immune. Extensive experiments demonstrate that SILoc and SILoc+ can achieve a centimeter-level localization accuracy in the scenario with an inconsistent or unknown robot moving speed.

关键词： Patch antenna   quarter-wavelength impedance transformer   RFID reader, directional antenna   phased array antenna   power divider  

摘要： This research paper deals with a directional high gain PCB 1 x 8 antenna array for 2.4 ISM band utilizations. To achieve this antenna array, a well-matched equal-split 9 dB-power splitter is designed and integrated with the suggested antenna array. It exhibits a wide operating range of 506MHz (2.022-2.528 GHz) and splits the feed power to 8 equal-in-phase output quantities. Then eight identical patch elements with good reflection coefficient, high gain and excellent radiation efficiency are connected at the eight-output ports of the 1 x 8-power divider in order to obtain an array antenna consisting of eight radiating elements. A quarter-wave impedance adapter is utilized to obtain a perfect matching of impedance between patches and the power divider. The suggested directional antenna resonates at 2.4GHz with good impedance matching via offering reflection coefficient S-11 = -24.34 dB and voltage standing wave ratio (VSWR) of 1.16. Moreover, it offers good radiation traits like the enhanced gain of 14.76 dB, an excellent radiating efficiency equals about 98.86% and a directional radiation pattern. Initially, the proposed planar directional antenna array has been designed and simulated utilizing high-frequency structure simulator (HFSS) EM simulation tool, the results are validated with another simulation tool via computer simulation technology (CST) software. This printed antenna array is a potential candidate to operate at around 2.4GHz for RFID reader utilizations due to its outstanding impedance and radiation characteristics.

关键词： cavity resonator   chipless RFID   electric field measurement   electromagnetic band gap   substrate-integrated waveguide   tunable resonator  

摘要： This paper presents a wireless chipless resonator-based sensor for measuring the absolute value of an external time-varying electric field. The sensor is developed using contactless air-filled substrate-integrated waveguide (CLAF-SIW) technology. The sensor employs a low-impedance electromagnetic band gap structure to confine the electric field within the sensor's air cavity. The air cavity is loaded with varactor diodes whose reverse bias voltage is modified by the to-be-measured external electric field. Variation in the external electric field results in a variation of the sensor's resonant frequency. The CLAF-SIW sensor offers a high unloaded quality factor, which is required for a long-distance ringback-based interrogation system. A prototype of the proposed sensor is fabricated and tested. It can measure a time-varying external electric field up to 6.9 kV/m, has a sensitivity of 1.86 (kHz)/(V/m), and can be interrogated from a distance of 80 cm. The feasible maximum bandwidth of the external electric field is 25 kHz. The proposed sensor offers a compact planar multilayer structure that can easily be incorporated with a planar antenna and its size can be reduced by selecting a higher operating frequency without an increase in dielectric loss.

关键词： Physical-layer identification   RFID   security  

摘要： Physical-layer identification uses manufacturing variations to create unique identifiers for each device. A decade ago, this concept was applied to RFID tags using backscatter frequency drift (BFD), a specific kind of 'fingerprint' determined by the difference between the actual backscatter signal received and the expected backscatter link frequency (BLF). However, BFD has been undervalued due to its low performance in tag identification, achieving less than 30% accuracy. In this study, we reevaluate BFD, focusing on the issue of frequency resolution as the cause of its poor performance. The problem doesn't lie in the BFD's uniqueness, but in the inferior way we measure the frequency of a backscatter signal, which is limited by the current air interface protocol. This situation is akin to trying to identify human fingerprints using low-quality imaging. We propose a practical solution to improve the frequency resolution from kilohertz to sub-hertz, without requiring hardware or protocol changes. Our findings show that this high-resolution BFD approach significantly enhances the distinguishability to 99.4% and the identification accuracy to 94% when tested on a dataset of 7,135 RFID tags across nine models.

关键词： Sensors   Radiofrequency identification   Frequency measurement   Feature extraction   Protocols   Frequency division multiplexing   Bandwidth   Internet of Things   RFID   wireless sensing  

摘要： RFID shows great potentials to build useful sensing applications. However, current RFID sensing can obtain mainly a single-dimensional sensing measurement from each reader-to-tag query, such as phase, RSS, etc. This is sufficient to fulfill the designs that are bound to the tag's movement, e.g., the localization of tags. However, it imposes inevitable uncertainty on many sensing tasks relying on the features extracted from the RFID signals. These traditional sensing measurements limit the fidelity of RFID sensing fundamentally and prevent its broader usage in more sophisticated sensing scenarios. This paper presents RF-Wise to push the limit of RFID-based sensing, motivated by an insightful observation to customize RFID signals. RF-Wise can enrich the existing single-dimensional feature measure to a channel state information (CSI)-like measure with up to 150-dimensional samples across different frequencies concurrently. More importantly, RF-Wise is a software solution atop the standard EPC Gen2 protocol without using any extra hardware. It requires only one tag for sensing and works within the ISM band. RF-Wise, so far as we know, is the first system of such a kind. Extensive experiments show that RF-Wise does not impact underlying RFID communications, while by using the features extracted by RF-Wise, applications' sensing performance can be improved remarkably. The source codes of RF-Wise are available at https://***/RF-WISE/.

关键词： downhole oil well   RFID reader   half duplex   sparse solenoid antenna  

摘要： RFID (Radio Frequency Identification), which transmits control data through electronic tags in a non-contact manner, provides a new approach for efficient and low-cost remote control of oil downhole tools. However, the interference of harsh downhole environments and the high-speed movement of tags seriously affect the performance of the current downhole reader. To effectively address this issue, in this study, a novel downhole RFID reader is presented. By introducing the half-duplex communication protocol to replace the current full-duplex communication protocol in the hardware circuits of the reader, its tag recognition ability can be improved. Then, the corresponding hardware circuits and software programs are designed. Furthermore, a sparse solenoid antenna is adopted to replace the traditional tightly wound solenoid antenna, which can provide a longer reading area range to cope with the high-moving tag, and its total length and spacing parameters between adjacent coils are designed in detail. The test results show that the proposed RFID reader based on a half-duplex communication protocol can communicate with tags normally, and its sparse solenoid antenna provides significantly more tag reading times than traditional tightly wound solenoid antennas under the same antenna inductance.

关键词： deep learning   indoor positioning   RFID   received signal strength  

摘要： This study presents a novel approach to indoor positioning leveraging radio frequency identification (RFID) technology based on received signal strength indication (RSSI). The proposed methodology integrates Gaussian Kalman filtering for effective signal preprocessing and a time-distributed auto encoder-gated recurrent unit (TAE-GRU) model for precise location prediction. Addressing the prevalent challenges of low accuracy and extended localization times in current systems, the proposed method significantly enhances the preprocessing of RSSI data and effectively captures the temporal relationships inherent in the data. Experimental validation demonstrates that the proposed approach achieves a 75.9% improvement in localization accuracy over simple neural network methods and markedly enhances the speed of localization, thereby proving its practical applicability in real-world indoor localization scenarios.