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Radio Frequency Identification (RFID) is considered a key element of the Internet of Things (IoT). It enables objects to be identified and tracked using radio waves. In RFID systems, several tags may be present within the range of the reader, leading to collisions and interference between signals that reduce system performance. Several anti-collision solutions have been proposed to solve this problem based on TDMA (Time-Division Multiple Access) technique, such as the ALOHA, Slotted ALOHA and Dynamic Framed Slotted ALOHA (DFSA) protocols. In this paper, we propose to improve TDMA anti-collision protocols based on the Cell Averaging Constant False Alarm Rate (CA-CFAR) scheme. The CA-CFAR technique is introduced to estimate the number of tags in the physical layer so that the reader can adjust its transmission parameters accordingly and avoid collisions. The obtained results show that this technique achieves good results in terms of system efficiency and the number of required slots to identify all the tags of the system. [ABSTRACT FROM AUTHOR]

Summary: The work presented in this paper aims to develop a low‐cost ultra‐wideband (UWB) radar system that has the capability to image through the wall of a human target. The proposed radar system relies heavily on a field‐programmable gate array (FPGA) platform. The Xilinx FPGA Kintex‐7 (KC705) board is employed to integrate the main functionalities of the radar system, such as the generation and acquisition of a UWB signal. The generated signal is a monocycle signal, which has an ultra‐wide bandwidth. Due to the UWB nature of this signal, the radar system achieves better penetration ability, as well as high imaging resolution. However, the major challenge of a UWB radar system lies in the stage of digitization, as it requires a high sampling rate analog‐to‐digital converter (ADC). In fact, such a chip is very expensive. Hence, to reach a high sampling resolution using a low‐cost and low‐speed ADC, an efficient sampling strategy is implemented. In contrast to other UWB sampling methods, which require a hardware delay line chip, the new sampling scheme depends only on the FPGA firmware to realize a combination of real‐time and equivalent‐time sampling, which provides better jitter performance. Finally, to demonstrate the imaging capability, experimental tests are conducted in an indoor environment while human targets are located in different places. The measurement results revealed that the proposed radar system has the ability to provide 2D images that accurately determine the location of the target. [ABSTRACT FROM AUTHOR]

High resolution Synthetic Aperture Radar (SAR) images are affected by speckle noise, which considerably reduces their visibility and complicates the target identification. In this paper, a new Compressive Sensing (CS) method is proposed to reduce the speckle noise effects of complex valued SAR images. The sparsity of the SAR images allows solving the CS problem using Multiple Measurements Vector (MMV) configuration. Therefore, a special weighted norm is constructed to solve the optimization problem, so that the Variance-Based Joint Sparsity (VBJS) model is used to calculate the weights. An efficient Alternating Direction Method of Multipliers (ADMM) is developed to solve the optimization problem. The obtained results using raw complex-valued measurements with ground truth demonstrate the effectiveness of the proposed despeckling method in terms of both image quality and computational cost. [ABSTRACT FROM AUTHOR]

Through-Wall-Imaging (TWI) radar offers considerable advantages for applications that require safety and security, such as disaster survivor rescue and tracking terrorist activities. In such situations, the use of an impulse UWB radar system is constantly increasing due to its ability to provide precise images of hidden targets in a short period of time. This paper presents a new radar system for through-wall imaging using an impulse-radio ultra-wideband (IR-UWB) signal. The radar system is built using a field-programmable gate array (FPGA) board, an oscilloscope, and Vivaldi antennas. The radar system transmits impulse signals, which have a monocycle shape with a 400-picosecond duration and a 4.6 GHz bandwidth. The FPGA board is used to produce impulse signals that have a short time duration in the sub-nanosecond range in order to expand the bandwidth of the generated signal and make the developed radar capable of providing high-resolution images. The FPGA-based implementation of the IR-UWB generator offers the flexibility to modify the spectrum characteristics of the generated signal. The receiver side of the radar system collects the echoes using the principle of synthetic aperture radar (SAR), and then the time-domain back-projection algorithm is applied to the radar echo to form 2D images. An indoor imaging experiment was carried out with two human targets to investigate the imaging capability of the designed IR-UWB radar. The obtained experimental results demonstrate that this radar has the potential to deliver high-resolution images of multiple human targets and identify their locations. [ABSTRACT FROM AUTHOR]

In this paper a new approach for designing invisible non-blind full crypto-watermarking system targeting images security on FPGA platform is presented. This new design is based on the Hardware-Software co-design approach using the High-Level Synthesis (HLS) tool of Xilinx which allows a good compromise between development time and performances. For a better authentication and robustness of the proposed system, the Discrete Wavelet Transform (DWT) is employed. To more enhance the security level, a new chaos-based generator proposed is integrated into a stream cipher algorithm in order to encrypt and decrypt the watermark during the insertion and extraction phases.This approach allows a better secure access at the positions of the watermark and to distribute the watermark evenly throughout the image. Three novel customized Intellectual Property (IP) cores designed under HLS tool, implementing Haar DWT and the new chaos-based key generator, have been generated, tested, and validated. The generated Register Transfer Level-IP (RTL-IP) cores are integrated into a Vivado library that achieves real-time secured watermarking operations for both embedding and extraction processes. The system has been evaluated using the main metrics in terms of imperceptibility of the produced watermarked images achieving a Peak Signal to Noise Ratio (PSNR) of 47 dB, robustness against most geometric and image processing attacks achieving a Normalized Cross-Correlation (NCC) of 0.99. The proposed crypt-watermarking system allows a good solution against brute force attack which produce a huge key-space of 2 768 . Finally, the implementation offers a good efficiency value of 0.19 MHz/LUT in terms of FPGA resource consumption and speed, making the system a reliable choice for real sensitive embedded applications. [ABSTRACT FROM AUTHOR]

Simultaneous localization and mapping is very essential for autonomous navigation when the mobile robot is navigating in unknown environment without a global positioning system. Various techniques to solve the simultaneous localization and mapping problem have been extensively studied using the combination of low-cost sensors. Most of the work in mobile robotics still consists of finding solutions to problems in data exchange between mobile robot and communication control station, which is a challenging task. In fact, communication systems impose severe constraints in terms of channel capacity and transmission quality, because the transmission channel in communication systems is undergoing at the different physical phenomena like scattering, diffusion and diffraction, which occur interference and multiple path effects in wireless communications, while keeping these effects levels low. This article describes a simultaneous localization and mapping problem based on second-order smooth variable structure filter embedded in mobile robot equipped with a sensor for data wireless collection. The inclusion of the control in environments outside the mobile robot field of view can make the wireless communication simultaneous localization and mapping process much more difficult to find a solution under realistic conditions. In order to solve the simultaneous localization and mapping issue and to mitigate the fading phenomena, which affect the quality of service in advanced wireless communication systems, we use a new approach to combat the fading effect without requiring any statistical knowledge of the propagation channel parameters. Several experiments have been done in real-world applications, and good performances were obtained using a second-order smooth variable structure filter–simultaneous localization and mapping algorithm–based wireless communication. [ABSTRACT FROM AUTHOR]

With the rapid development of microelectronics devices and the progress in communication and information technologies, many services and technologies are increasingly involved into our daily life. In fact, as the used systems are progressively interconnected and open, this introduce new threats such as more and more hacking, fraud and many other kinds of misuses. Consequently, the security and privacy of the exchanged data information tampering must be addressed most seriously. In this context, recently Elliptic Curve Cryptography (ECC) is widely used in many cryptosystems nowadays especially for those presenting challenging constraints in terms of power consumption, memory, computational cost, etc. It is well-known that the ECC provides high security level with much smaller key sizes. In this paper, we show that an inappropriate use of ECC cryptographic primitives, the lack of experience in designing secure protocols and the unsuitable choice of security verification tools can destroy the whole security of a given ECC-based scheme. Therefore, first we wreck efficient attacks on three most recent proposed ECC-based protocols published in three of well-known scientific journals. Then, an improved protocol that inherits the strengths of Dinarvand and Barati's protocol and takes into account the discovered flaws is proposed. Via formal and informal security models, we assess that the improved protocol could deliver all the virtues of Dinarvand and Barati's protocol and resists all known attacks. [ABSTRACT FROM AUTHOR]

Nowadays, diagnosing patient diseases remotely is a routine and digital medical images analysis as a part of Telecare Medical Information Systems (TMIS) play a fundamental role in early diagnosing and treating most common and serious diseases such as breast cancer. In this context, altering or distorting even a single pixel of a medical image during its transmission over an unsure channel could lead to a wrong diagnosis and harm patient health, induce damaging delays. Therefore the security and privacy of the transmitted medical images must be addressed most seriously. Several techniques are proposed in the literature to address these issues using different techniques such as chaos theory, more recently, elliptic curves cryptography (ECC) or improved classical methods such as linear cryptography. In this paper, we address the security level concern of an image encryption technique combining ECC with Hill cipher (ECCHC) which has been recently proposed by Dawahdeh et al [13]. Our study rises concerns about some weaknesses and flaws of the analyzed encryption scheme against some plain-text and known plain-text attacks. In addition, and not least issue, it is found that the key length used in Dawahdeh et al. scheme is not sufficiently large to be robust against brute force attack. To fix the found flaws and to improve the encryption scheme, a generalized cryptosystem is suggested. In the enhanced version, the key matrix negotiation is redefined to a cipher that combines a modified EC Integrated Encryption Scheme (ECIES) and the linear multiplication matrix is generalized to key matrix of (2n × 2n), n > 2 to counter efficiently the exhaustive search attack. The effectiveness of the proposed version is evaluated and verified through extensive experimentation and most recent available security tools. Compared with the state-of-the art techniques, the proposed version exhibits excellent security features and can resist to various knowing attacks. [ABSTRACT FROM AUTHOR]

Summary: In this paper, a new robust auto‐adaptive approach for pseudo‐noise (PN) code acquisition is proposed. It is applied to the generalized multi‐carrier direct‐sequence code‐division multiple‐access (MC DS‐CDMA) systems communicating over frequency‐selective multipath Rayleigh fading channels. This new approach is based on the constant false alarm rate (CFAR) detection algorithm, referred here as automatic selection partial sum ordered statistics (ASPSOS)‐CFAR. The proposed approach does not require any prior information about the background environment and uses maximum likelihood estimation (MLE) method to detect the interfering signals group in the ranked cells for the full reference window. Once this group is identified and censored, the remaining smaller ranked cells are combined to form an estimate of the background noise level to compute the adaptive threshold. Through simulations, the performance of the proposed detector is analyzed and compared with traditional CFAR detectors based on fixed or automatic censoring algorithms. The obtained results show that the proposed detector eliminates the drawbacks of the previously related detectors and offers a robust detection performance to enhance the acquisition process in heterogeneous background environments. [ABSTRACT FROM AUTHOR]

This letter presents a proportional adaptive technique to mitigate the multipath fading effect in advanced wireless communication systems. The designed system consists of a realized ultra‐wideband (UWB) dual antenna array and two universal software radio peripheral (USRP) platforms synchronized by a MIMO cable, with one digital RF phase shifter implemented in the reception chain of one of the two receiving antennas. Without requiring any statistical knowledge channel, the proposed approach adjusts the phase shifter in order to maximize the combined received power proportionally to the amplitude of its gradient. The used antennas operate in different frequencies in the fifth‐generation (Sub‐6 GHz 5G) wireless communication applications. The proposed algorithm has been implemented on a USRP that has been used to carry out experimental measurements on fixed and mobile receiving antennas, and it is compared with other approaches. The measurements reveal, that using the amplitude of the gradient of the received power rather than its sign, as it is proposed in the initial on‐off algorithm presented in a previous published work, allows achieving better performance in combatting fading. The phase adjustment with the proposed algorithm is more efficient than in the other approaches allowing a better reception of the received signal with a higher received power level. The measured performances indicate that gain improvement of 8 to 10 dB can be achieved by using the proportional adaptive technique. [ABSTRACT FROM AUTHOR]

Summary: This paper presents a new efficient and lightweight approach for enhancing the security of biometric models, namely, fingerprint templates, against possible attacks. The proposed design is based on Vernam stream cipher in which the key generator is designed in the hardware manner. The designed cryptosystem consists of using multi‐scroll chaotic system that is characterized by a large key space and can be generated N×N grid multi‐scroll attractors, with a good behavior of chaotic dynamic. The hardware approach is carried out through describing Euler method by VHDL. Field‐programmable gate array (FPGA) experimental results validate the developed architecture while still providing a good compromise between hardware resources and performance. Indeed, security analysis also shows that the designed encryption algorithm is robust against statistical, brute force, and entropy attacks. Therefore, it can be considered as a lightweight security solution, which could be very useful in many embedded applications namely securing biometric authentication systems. [ABSTRACT FROM AUTHOR]

A novel estimation scheme that combines Bayesian and lower bound estimating radio frequency identification tag population size is proposed. The developed methodology is based on the fusion between the Bayesian and lower bound estimating techniques. It turns out that the fusion rule is built up thanks to an existing linear relationship between the cited techniques. Simulation results show that the developed technique significantly improves the accuracy of the estimating tag quantity and presents less estimation error. Also, the resulting advanced dynamic framed slotted ALOHA protocol considerably improves the performance and efficiency of the radio frequency identification anti-collision compared with the most recent protocols using others estimating methods. [ABSTRACT FROM AUTHOR]

Radio frequency identification (RFID) is a promising wireless emerging technology for automatic objects identification. This technology is widely deployed in numerous applications and is becoming popular in health-care environments. Many health-care services, such as patient monitoring, drug administration systems, and telecare medicine information systems, are automated and powered by the RFID technology. This rigorous redeployment is done to improve the quality and effectiveness of patient care and many other aspects. Henceforth, the confidentiality and privacy of the personal electronic health-care information become progressively challenging. In this context, with more and more significant and rigorous security requirements, elliptic curve cryptography has been intensively suggested to design efficient RFID authentication protocols. In this paper, we propose a secure mobile RFID authentication protocol to increase the safety of the patient data records and the work efficiency of medical staff. Our proposal uses the elliptic curve signature with message recovery. To the best of our knowledge, it is the first time the elliptic curve signature with message recovery signature is introduced for RFID medical applications. The proposed protocol is validated using field programmable gate arrays) technology. In addition, via formal and informal security analysis, we show that our proposal could solve security weaknesses of some previously proposed protocols, provide mobility, privacy, scalability, and can be adapted for multiserver environment. [ABSTRACT FROM AUTHOR]

Radio frequency identification (RFID) technology has been used in a wide variety of applications, more recently as a leading identification technology in healthcare environments. In the most recent years, this technology is adopted for telecare medicine information system (TMIS) for authentication, safety, security, data confidentiality and patient's privacy protection over public networks. TMIS is the bridge between patients at home and doctors at healthcare organizations that permits to confirm the correctness of exchanged information between different actors of the system. Recently, several RFID authentication schemes have been presented and suggested for the TMIS in the literature. These schemes try to resolve the security and privacy problems over insecure healthcare networks environments by exploiting different cryptographic primitive's solutions. In this paper, we analyze in depth the security of the most recent proposed protocol for TMIS in the literature and find out its main vulnerabilities. The proposed attacks are possible due to some weaknesses related to the misuse of the timestamp technique, the calculation of the reader request and tag response messages using the one-way hash function, which are not attentively scrutinized. Furthermore, we propose an efficient and robust improved mobile authentication protocol with high efficiency and security for TMIS. The performance analysis shows that our improved protocol could solve security weaknesses of the studied protocol and provide mobility, efficiency and is well-suited to adoption for TMIS. [ABSTRACT FROM AUTHOR]

Radio frequency identification technology is one of the modern popular emerging technologies proven to advance a wide range of applications in both academia and industry. However, potential security risks, privacy issues, and efficiency are still open challenges that must be addressed seriously to achieve enhanced protection. In this paper, we show that the Akgün et al. protocol remains unsafe and imperfect in terms of the security issue and database identification efficiency. We, first, demonstrate that the Akgün et al. protocol suffers from a stolen/lost reader attack, which could expose users to some life threatening situations and unwanted collection of sensitive private information. Second, we found that all indexing identification-based protocols and exceptionally the Akgün et al. protocol cannot be used properly when the collision of tag index occurs, which exhibits a low efficiency in the database entry identification process. As the Akgün et al. protocol is almost perfect, it is worthy to be enhanced. Therefore, towards a complete and secure mobile radio frequency identification authentication protocol, we propose efficient solutions that could overcome the aforementioned security problem and offer high identification efficiency using efficient anticollision procedure based on dynamic linked list data structure principle. Via informal and formal security analysis, we show that the improved version is insensitive to the most common attacks and is more efficient than the existing schemes in the literature. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Radio Frequency IDentification (RFID) technology is used in a wide variety of applications, more recently as a leading identification technology in healthcare environments. In the most recent years, this technology has been adopted for telecare medicine information system (TMIS) for authentication, safety, security, data confidentiality, and patient's privacy protection over public networks. TMIS is the bridge between patients at home and doctors at healthcare organizations that permits to validate the correctness of exchanged information between different actors of the system. Recently, several RFID and smart cards authentication schemes have been presented and suggested for the TMIS in the literature. These schemes try to resolve the security and privacy problems over insecure healthcare network environments by exploiting different cryptographic primitive's solutions. In this paper, we first highlighted the vulnerabilities of the most recent proposed protocol for TMIS in the literature and proposed attacks based on the weaknesses related to the misuse of the timestamp technique, the calculation of the reader request and tag response messages using the one-way hash function, which are not attentively scrutinized. Second, we propose an efficient dual RFID-TMIS mobile authentication protocol with high efficiency and security for healthcare systems. Our proposal is an improvement and extension of the protocol of Li et al., where we propose to associate the RFID technology with TMIS in the same authentication system to take advantages of both these two promising technologies. The performance analysis shows that our improved protocol could solve security weaknesses of the studied protocol and provide mobility, efficiency and is well suited for TMIS adoption in remote areas and low population density. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT With the fast growth of the automatic authentication and asset tracking usage in a wide variety of applications in different fields, government, logistics, transportation and retail are among the most supportive of the radio-frequency identification (RFID) market. Security is a crucial issue and must be addressed seriously. RFID security must meet the public demand of data protection. Recently, several lightweight RFID authentication protocols conforming to the EPCglobal Class 1 Generation 2 (EPC C1-G2) standard have been proposed. In this paper, we present efficient attacks against the authenticated RFID security mechanism of Chang et al. based on Chebyshev chaotic maps, which is the first solution that adopted the chaos in the RFID authentication process. It turns out that this protocol has fundamental weaknesses that can be used by an adversary to break the system. We will show that this protocol is vulnerable to tracking attack, secret disclosure attack, impersonation attack and desynchronization attack. The proposed attack techniques are in light of two flaws related to the message generation and the shared-secret update process, which are not neatly scrutinized. Then, we propose an improved RFID authentication protocol based on the Chebyshev chaotic map hard problem, conforming to the EPC C1-G2 standard with more flexibility, security and mobility for the RFID application. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]