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Haase, Julian, Jaster, Sebastian, Franz, Elke, Göhringer, Diana.  2022.  Secure Communication Protocol for Network-on-Chip with Authenticated Encryption and Recovery Mechanism. 2022 IEEE 33rd International Conference on Application-specific Systems, Architectures and Processors (ASAP). :156—160.
In recent times, Network-on-Chip (NoC) has become state of the art for communication in Multiprocessor System-on-Chip due to the existing scalability issues in this area. However, these systems are exposed to security threats such as extraction of secret information. Therefore, the need for secure communication arises in such environments. In this work, we present a communication protocol based on authenticated encryption with recovery mechanisms to establish secure end-to-end communication between the NoC nodes. In addition, a selected key agreement approach required for secure communication is implemented. The security functionality is located in the network adapter of each processing element. If data is tampered with or deleted during transmission, recovery mechanisms ensure that the corrupted data is retransmitted by the network adapter without the need of interference from the processing element. We simulated and implemented the complete system with SystemC TLM using the NoC simulation platform PANACA. Our results show that we can keep a high rate of correctly transmitted information even when attackers infiltrated the NoC system.
Albayrak, Cenk, Arslan, Hüseyin, Türk, Kadir.  2022.  Physical Layer Security for Visible Light Communication in the Presence of ISI and NLoS. 2022 IEEE International Conference on Communications Workshops (ICC Workshops). :469–474.
Visible light communication (VLC) is an important alternative and/or complementary technology for next generation indoor wireless broadband communication systems. In order to ensure data security for VLC in public areas, many studies in literature consider physical layer security (PLS). These studies generally neglect the reflections in the VLC channel and assume no inter symbol interference (ISI). However, increasing the data transmission rate causes ISI. In addition, even if the power of the reflections is small compared to the line of sight (LoS) components, it can affect the secrecy rate in a typical indoor VLC system. In this study, we investigate the effects of ISI and reflected channel components on secrecy rate in multiple-input single-output (MISO) VLC scenario utilized null-steering (NS) and artificial noise (AN) PLS techniques.
ISSN: 2694-2941
Khodayer Al-Dulaimi, Omer Mohammed, Hassan Al-Dulaimi, Mohammed Khodayer, Khodayer Al-Dulaimi, Aymen Mohammed.  2022.  Analysis of Low Power Wireless Technologies used in the Internet of Things (IoT). 2022 2nd International Conference on Computing and Machine Intelligence (ICMI). :1-6.

The Internet of Things (IoT) is a novel paradigm that enables the development of a slew of Services for the future of technology advancements. When it comes to IoT applications, the cyber and physical worlds can be seamlessly integrated, but they are essentially limitless. However, despite the great efforts of standardization bodies, coalitions, companies, researchers, and others, there are still a slew of issues to overcome in order to fully realize the IoT's promise. These concerns should be examined from a variety of perspectives, including enabling technology, applications, business models, and social and environmental consequences. The focus of this paper is on open concerns and challenges from a technological standpoint. We will study the differences in technical such Sigfox, NB-IoT, LoRa, and 6LowPAN, and discuss their advantages and disadvantage for each technology compared with other technologies. Demonstrate that each technology has a position in the internet of things market. Each technology has different advantages and disadvantages it depends on the quality of services, latency, and battery life as a mention. The first will be analysis IoT technologies. SigFox technology offers a long-range, low-power, low-throughput communications network that is remarkably resistant to environmental interference, enabling information to be used efficiently in a wide variety of applications. We analyze how NB-IoT technology will benefit higher-value-added services markets for IoT devices that are willing to pay for exceptionally low latency and high service quality. The LoRa technology will be used as a low-cost device, as it has a very long-range (high coverage).

Özmat, Utku, Demirkol, Mehmet Fatih, Demirci, Nuran, Yazıcı, Mehmet Akif.  2020.  Enhancing Physical Layer Security with Coordinated Multi-Point Transmission in 5G and Beyond Networks. 2020 28th Signal Processing and Communications Applications Conference (SIU). :1–4.
Physical layer security has gained importance with the widespread use of wireless communication systems. Multiantenna systems and multi-point transmission techniques in 5G and beyond are promising techniques not only for enhancing data rates, but also physical layer security. Coordinated multipoint transmission is used for enhancing the service quality and decreasing inter-cell interference especially for cell-edge users. In this study, analysis of physical layer security enhancement via multi-antenna technologies and coordinated multi-point for 5G and beyond networks is provided. The proposed scheme is evaluated on calculations from real-life mobile network topologies. As a figure of performance, the secure and successful detection probability is computed with varying antenna array size, number of coordinated transmission points, and different service requirements.
Xu, Zhifan, Baykal-Gürsoy, Melike, Spasojević, Predrag.  2021.  A Game-Theoretic Approach for Probabilistic Cooperative Jamming Strategies over Parallel Wireless Channels. 2021 IEEE Conference on Communications and Network Security (CNS). :47–55.
Considered is a network of parallel wireless channels in which individual parties are engaged in secret communication under the protection of cooperative jamming. A strategic eavesdropper selects the most vulnerable channels to attack. Existing works usually suggest the defender allocate limited cooperative jamming power to various channels. However, it usually requires some strong assumptions and complex computation to find such an optimal power control policy. This paper proposes a probabilistic cooperative jamming scheme such that the defender focuses on protecting randomly selected channels. Two different cases regarding each channel’s eavesdropping capacity are discussed. The first case studies the general scenario where each channel has different eavesdropping capacity. The second case analyzes an extreme scenario where all channels have the same eavesdropping capacity. Two non-zero-sum Nash games model the competition between the network defender and an eavesdropper in each case. Furthermore, considering the case that the defender does not know the eavesdropper’s channel state information (CSI) leads to a Bayesian game. For all three games, we derive conditions for the existence of a unique Nash equilibrium (NE), and obtain the equilibria and the value functions in closed form.
Liu, Yulin, Han, Guangjie, Wang, Hao, Jiang, Jinfang.  2021.  FPTSA-SLP: A Fake Packet Time Slot Assignment-based Source Location Privacy Protection Scheme in Underwater Acoustic Sensor Networks. 2021 Computing, Communications and IoT Applications (ComComAp). :307–311.
Nowadays, source location privacy in underwater acoustic sensor networks (UASNs) has gained a lot of attention. The aim of source location privacy is to use specific technologies to protect the location of the source from being compromised. Among the many technologies available are fake packet technology, multi-path routing technology and so on. The fake packet technology uses a certain amount of fake packets to mask the transmission of the source packet, affecting the adversary's efficiency of hop-by-hop backtracking to the source. However, during the operation of the fake packet technology, the fake packet, and the source packet may interfere with each other. Focus on this, a fake packet time slot assignment-based source location privacy protection (FPTSA-SLP) scheme. The time slot assignment is adopted to avoid interference with the source packet. Also, a relay node selection method based on the handshake is further proposed to increase the diversity of the routing path to confuse the adversary. Compared with the comparison algorithm, the simulation results demonstrate that the proposed scheme has a better performance in safety time.
Zhang, Zhengjun, Liu, Yanqiang, Chen, Jiangtao, Qi, Zhengwei, Zhang, Yifeng, Liu, Huai.  2021.  Performance Analysis of Open-Source Hypervisors for Automotive Systems. 2021 IEEE 27th International Conference on Parallel and Distributed Systems (ICPADS). :530–537.
Nowadays, automotive products are intelligence intensive and thus inevitably handle multiple functionalities under the current high-speed networking environment. The embedded virtualization has high potentials in the automotive industry, thanks to its advantages in function integration, resource utilization, and security. The invention of ARM virtualization extensions has made it possible to run open-source hypervisors, such as Xen and KVM, for embedded applications. Nevertheless, there is little work to investigate the performance of these hypervisors on automotive platforms. This paper presents a detailed analysis of different types of open-source hypervisors that can be applied in the ARM platform. We carry out the virtualization performance experiment from the perspectives of CPU, memory, file I/O, and some OS operation performance on Xen and Jailhouse. A series of microbenchmark programs have been designed, specifically to evaluate the real-time performance of various hypervisors and the relevant overhead. Compared with Xen, Jailhouse has better latency performance, stable latency, and little interference jitter. The performance experiment results help us summarize the advantages and disadvantages of these hypervisors in automotive applications.
Liu, Nathan, Moreno, Carlos, Dunne, Murray, Fischmeister, Sebastian.  2021.  vProfile: Voltage-Based Anomaly Detection in Controller Area Networks. 2021 Design, Automation & Test in Europe Conference & Exhibition (DATE). :1142–1147.
Modern cars are becoming more accessible targets for cyberattacks due to the proliferation of wireless communication channels. The intra-vehicle Controller Area Network (CAN) bus lacks authentication, which exposes critical components to interference from less secure, wirelessly compromised modules. To address this issue, we propose vProfile, a sender authentication system based on voltage fingerprints of Electronic Control Units (ECUs). vProfile exploits the physical properties of ECU output voltages on the CAN bus to determine the authenticity of bus messages, which enables the detection of both hijacked ECUs and external devices connected to the bus. We show the potential of vProfile using experiments on two production vehicles with precision and recall scores of over 99.99%. The improved identification rates and more straightforward design of vProfile make it an attractive improvement over existing methods.
Zhu, Zhen, Chi, Cheng, Zhang, Chunhua.  2021.  Spatial-Resampling Wideband Compressive Beamforming. OCEANS 2021: San Diego – Porto. :1—4.
Compressive beamforming has been successfully applied to the estimation of the direction of arrival (DOA) of array signals, and has higher angular resolution than traditional high-resolution beamforming methods. However, most of the existing compressive beamforming methods are based on narrow signal models. Wideband signal processing using these existing compressive beamforming methods is to divide the frequency band into several narrow-bands and add up the beamforming results of each narrow-band. However, for sonar application, signals usually consist of continuous spectrum and line spectrum, and the line spectrum is usually more than 10dB higher than the continuous spectrum. Due to the large difference of signal-to-noise ratio (SNR) of each narrow-band, different regularization parameters should be used, otherwise it is difficult to get an ideal result, which makes compressive beamforming highly complicated. In this paper, a compressive beamforming method based on spatial resampling for uniform linear arrays is proposed. The signals are converted into narrow-band signals by spatial resampling technique, and compressive beamforming is then performed to estimate the DOA of the sound source. Experimental results show the superiority of the proposed method, which avoids the problem of using different parameters in the existing compressive beamforming methods, and the resolution is comparable to the existing methods using different parameters for wideband models. The spatial-resampling compressive beamforming has a better robustness when the regularization parameter is fixed, and exhibits lower levels of background interference than the existing methods.
Perarasi, T., Vidhya, S., Moses M., Leeban, Ramya, P..  2020.  Malicious Vehicles Identifying and Trust Management Algorithm for Enhance the Security in 5G-VANET. 2020 Second International Conference on Inventive Research in Computing Applications (ICIRCA). :269—275.
In this fifth generation of vehicular communication, the security against various malicious attacks are achieved by using malicious vehicles identification and trust management (MAT) algorithm. Basically, the proposed MAT algorithm performs in two dimensions, they are (i) Node trust and (ii) information trust accompanied with a digital signature and hash chain concept. In node trust, the MAT algorithm introduces the special form of key exchanging algorithm to every members of public group key, and later the vehicles with same target location are formed into cluster. The public group key is common for each participant but everyone maintain their own private key to produce the secret key. The proposed MAT algorithm, convert the secrete key into some unique form that allows the CMs (cluster members) to decipher that secrete key by utilizing their own private key. This key exchanging algorithm is useful to prevent the various attacks, like impersonate attack, man in middle attack, etc. In information trust, the MAT algorithm assigns some special nodes (it has common distance from both vehicles) for monitoring the message forwarding activities as well as routing behavior at particular time. This scheme is useful to predict an exact intruder and after time out the special node has dropped all the information. The proposed MAT algorithm accurately evaluates the trustworthiness of each node as well as information to control different attacks and become efficient for improving a group lifetime, stability of cluster, and vehicles that are located on their target place at correct time.
Camilo, Marcelo, Moura, David, Salles, Ronaldo.  2021.  Combined Interference and Communications strategy evaluation as a defense mechanism in typical Cognitive Radio Military Networks. 2021 International Symposium on Networks, Computers and Communications (ISNCC). :1—8.
Physical layer security has a paramount importance in tactical wireless networks. Traditional approaches may not fulfill all requirements, demanding additional sophisticated techniques. Thus, Combined Interference and Communications (CIC) emerges as a strategy against message interception in Cognitive Radio Military Networks (CRMN). Since CIC adopts an interference approach under specific CRMN requirements and characteristics, it saves great energy and reduces the receiver detection factor when compared to previous proposals in the literature. However, previous CIC analyses were conducted under vaguely realistic channel models. Thus, the focus of this paper is two-fold. Firstly, we identify more realistic channel models to achieve tactical network scenario channel parameters. Additionally, we use such parameters to evaluate CIC suitability to increase CRMN physical layer security. Numerical experiments and emulations illustrate potential impairments on previous work due to the adoption of unrealistic channel models, concluding that CIC technique remains as an upper limit to increase physical layer security in CRMN.
Wang, Xin, Ma, Xiaobo, Qu, Jian.  2021.  A Link Flooding Attack Detection Method based on Non-Cooperative Active Measurement. 2021 8th International Conference on Dependable Systems and Their Applications (DSA). :172–177.
In recent years, a new type of DDoS attacks against backbone routing links have appeared. They paralyze the communication network of a large area by directly congesting the key routing links concerning the network accessibility of the area. This new type of DDoS attacks make it difficult for traditional countermeasures to take effect. This paper proposes and implements an attack detection method based on non-cooperative active measurement. Experiments show that our detection method can efficiently perceive changes of network link performance and assist in identifying such new DDoS attacks. In our testbed, the network anomaly detection accuracy can reach 93.7%.
Kızmaz, Muhammed Mustafa, Ergün, Salih.  2021.  Skew-Tent Map Based CMOS Random Number Generator with Chaotic Sampling. 2021 19th IEEE International New Circuits and Systems Conference (NEWCAS). :1—4.
Random number generators (RNGs) has an extensive application area from cryptography to simulation software. Piecewise linear one-dimensional (PL1D) maps are commonly preferred structures used as the basis of RNGs due to their theoretically proven chaotic behavior and ease of implementation. In this work, a skew-tent map based RNG is designed by using the chaotic sampling method in TSMC 180 nm CMOS process. Simulation data of the designed RNG is validated by the statistical randomness tests of the FIPS-140-2 and NIST 800-22 suites. The proposed RNG has three key features: the generated bitstreams can fulfill the randomness tests without using any post processing methods; the proposed RNG has immunity against external interference thanks to the chaotic sampling method; and higher bitrates (4.8 Mbit/s) can be achieved with relatively low power consumption (9.8 mW). Thus, robust RNG systems can be built for high-speed security applications with low power by using the proposed architecture.
Cao, Yu.  2021.  Digital Character CAPTCHA Recognition Using Convolution Network. 2021 2nd International Conference on Computing and Data Science (CDS). :130—135.
Completely Automated Public Turing test to tell Computers and Humans Apart (CAPTCHA) is a type of automatic program to determine whether the user is human or not. The most common type of CAPTCHA is a kind of message interpretation by twisting the letters and adding slight noises in the background, plays a role of verification code. In this paper, we will introduce the basis of Convolutional Neural Network first. Then based on the handwritten digit recognition using CNN, we will develop a network for CAPTCHA image recognition.
Vallabhu, Satya Krishna, Maheswari, Nissankararao Uma, Kaveri, Badavath, Jagadeeswari, C..  2021.  Biometric Steganography Using MPV Technique. 2021 IEEE 6th International Conference on Computing, Communication and Automation (ICCCA). :39–43.
Biometric data is prone to attacks and threats from hackers who are professionals in cyber-crimes. Therefore, securing the data is very essential. Steganographic approach, which is a process of concealing data, is proposed as a solution to this. Biometrics are hidden inside other biometrics for safe storage and secure transmission. Also, it is designed to be robust against attacks, and cannot be detected easily. The intention of this paper is to highlight a method of hiding one image in another image by using mid position value(mpv) technique. Here we have to choose the secret biometric on which Arnold transform will be applied resulting in a scrambled version of the secret biometric. This will be enveloped inside cover image which results in a stego-image. Lastly, hidden secret biometric will be decoded from this stego image, which will first result in a scrambled secret biometric. Inverse Arnold Transform will be applied on this to finally result in the decoded secret biometric. The paper further explains the working and processes in detail.
Yasa, Ray Novita, Buana, I Komang Setia, Girinoto, Setiawan, Hermawan, Hadiprakoso, Raden Budiarto.  2021.  Modified RNP Privacy Protection Data Mining Method as Big Data Security. 2021 International Conference on Informatics, Multimedia, Cyber and Information System (ICIMCIS. :30–34.
Privacy-Preserving Data Mining (PPDM) has become an exciting topic to discuss in recent decades due to the growing interest in big data and data mining. A technique of securing data but still preserving the privacy that is in it. This paper provides an alternative perturbation-based PPDM technique which is carried out by modifying the RNP algorithm. The novelty given in this paper are modifications of some steps method with a specific purpose. The modifications made are in the form of first narrowing the selection of the disturbance value. With the aim that the number of attributes that are replaced in each record line is only as many as the attributes in the original data, no more and no need to repeat; secondly, derive the perturbation function from the cumulative distribution function and use it to find the probability distribution function so that the selection of replacement data has a clear basis. The experiment results on twenty-five perturbed data show that the modified RNP algorithm balances data utility and security level by selecting the appropriate disturbance value and perturbation value. The level of security is measured using privacy metrics in the form of value difference, average transformation of data, and percentage of retains. The method presented in this paper is fascinating to be applied to actual data that requires privacy preservation.
Pham, Thanh V., Pham, Anh T..  2021.  Energy-Efficient Friendly Jamming for Physical Layer Security in Visible Light Communication. 2021 IEEE International Conference on Communications Workshops (ICC Workshops). :1–6.
This work studies an energy-efficient jamming scheme for enhancing physical layer security in visible light communication (VLC). We consider a VLC system where multiple LED luminaries are deployed together with a legitimate user (i.e., Bob) and passive eavesdroppers (i.e., Eves). In such a scenario, the closest LED luminary to Bob serves as the transmitter while the rest of the luminaries act as jammers transmitting artificial noise (AN) to possibly degrade the quality of Eves' channels. A joint design of precoder and AN is then investigated to maximize the energy efficiency (EE) of the communication channel to Bob while ensuring a certain amount of AN power to confuse Eves. To solve the design problem, we make use of a combination of the Dinkelbach and convex-concave procedure (CCCP), which guarantees to converge to a local optimum.
Junqing, Zhang, Gangqiang, Zhang, Junkai, Liu.  2021.  Wormhole Attack Detecting in Underwater Acoustic Communication Networks. 2021 OES China Ocean Acoustics (COA). :647—650.

Because the underwater acoustic communication network transmits data through the underwater acoustic wireless link, the Underwater Acoustic Communication Network is easy to suffer from the external artificial interference, in this paper, the detection algorithm of wormhole attack in Underwater Acoustic Communication Network based on Azimuth measurement technology is studied. The existence of wormhole attack is judged by Azimuth or distance outliers, and the security performance of underwater acoustic communication network is evaluated. The influence of different azimuth direction errors on the detection probability of wormhole attack is analyzed by simulation. The simulation results show that this method has a good detection effect for Underwater Acoustic Communication Network.

Yamanokuchi, Koki, Watanabe, Hiroki, Itoh, Jun-Ichi.  2021.  Universal Smart Power Module Concept with High-speed Controller for Simplification of Power Conversion System Design. 2021 IEEE 12th Energy Conversion Congress Exposition - Asia (ECCE-Asia). :2484–2489.
This paper proposes the modular power conversion systems based on an Universal Smart Power Module (USPM). In this concept, the Power Electronics Building Block (PEBB) is improved the flexibility and the expandability by integrating a high-speed power electronics controller, input/output filters among each USPM to realize the simplification of the power electronics design. The original point of USPM is that each power module operates independently because a high-speed power electronics controller is implemented on each power module. The power modules of PEBB are typically configured by the main power circuits and the gate driver. Therefore, the controller has to be designed specifically according to various applications although the advantages of PEBB are high flexibility and user-friendly. The contribution of USPM is the simplification of the system design including power electronics controller. On the other hand, autonomous distributed systems require the control method to suppress the interference in each module. In this paper, the configuration of USPM, example of the USPM system, and detail of the control method are introduced.
Hörmann, Leander B., Pötsch, Albert, Kastl, Christian, Priller, Peter, Springer, Andreas.  2021.  Towards a Distributed Testbed for Wireless Embedded Devices for Industrial Applications. 2021 17th IEEE International Conference on Factory Communication Systems (WFCS). :135–138.
Wireless embedded devices are key elements of Internet-of-Things (IoT) and industrial IoT (IIoT) applications. The complexity of these devices as well as the number of connected devices to networks increase steadily. The high intricacy of the overall system makes it error-prone and vulnerable to attacks and leads to the need to test individual parts or even the whole system. Therefore, this paper presents the concept of a flexible and distributed testbed to evaluate correct behavior in various operation or attack scenarios. It is based on the Robot Operating System (ROS) as communication framework to ensure modularity and expandability. The testbed integrates RF-jamming and measurement devices to evaluate remote attack scenarios and interference issues. An energy harvesting emulation cell is used to evaluate different real-world energy harvesting scenarios. A climatic test chamber allows to investigate the influence of temperature and humidity conditions on the system-under-test. As a testbed application scenario, the automated evaluation of an energy harvesting wireless sensor network designed to instrument automotive engine test benches is presented.
Xu, Jun, Zhu, Pengcheng, Li, Jiamin, You, Xiaohu.  2021.  Secure Computation Offloading for Multi-user Multi-server MEC-enabled IoT. ICC 2021 - IEEE International Conference on Communications. :1—6.

This paper studies the secure computation offloading for multi-user multi-server mobile edge computing (MEC)-enabled internet of things (IoT). A novel jamming signal scheme is designed to interfere with the decoding process at the Eve, but not impair the uplink task offloading from users to APs. Considering offloading latency and secrecy constraints, this paper studies the joint optimization of communication and computation resource allocation, as well as partial offloading ratio to maximize the total secrecy offloading data (TSOD) during the whole offloading process. The considered problem is nonconvex, and we resort to block coordinate descent (BCD) method to decompose it into three subproblems. An efficient iterative algorithm is proposed to achieve a locally optimal solution to power allocation subproblem. Then the optimal computation resource allocation and offloading ratio are derived in closed forms. Simulation results demonstrate that the proposed algorithm converges fast and achieves higher TSOD than some heuristics.

Qin, Desong, Zhang, Zhenjiang.  2021.  A Frequency Estimation Algorithm under Local Differential Privacy. 2021 15th International Conference on Ubiquitous Information Management and Communication (IMCOM). :1–5.

With the rapid development of 5G, the Internet of Things (IoT) and edge computing technologies dramatically improve smart industries' efficiency, such as healthcare, smart agriculture, and smart city. IoT is a data-driven system in which many smart devices generate and collect a massive amount of user privacy data, which may be used to improve users' efficiency. However, these data tend to leak personal privacy when people send it to the Internet. Differential privacy (DP) provides a method for measuring privacy protection and a more flexible privacy protection algorithm. In this paper, we study an estimation problem and propose a new frequency estimation algorithm named MFEA that redesigns the publish process. The algorithm maps a finite data set to an integer range through a hash function, then initializes the data vector according to the mapped value and adds noise through the randomized response. The frequency of all interference data is estimated with maximum likelihood. Compared with the current traditional frequency estimation, our approach achieves better algorithm complexity and error control while satisfying differential privacy protection (LDP).

Mu, Jing, Jia, Xia.  2021.  Simulation and Analysis of the Influence of Artificial Interference Signal Style on Wireless Security System Performance. 2021 IEEE 4th Advanced Information Management, Communicates, Electronic and Automation Control Conference (IMCEC). 4:2106–2109.
Aimming at the severe security threat faced by information transmission in wireless communication, the artificial interference in physical layer security technology was considered, and the influence of artificial interference signal style on system information transmission security was analyzed by simulation, which provided technical accumulation for the design of wireless security transmission system based on artificial interference.
Tian, Qian, Song, Qishun, Wang, Hongbo, Hu, Zhihong, Zhu, Siyu.  2021.  Verification Code Recognition Based on Convolutional Neural Network. 2021 IEEE 4th Advanced Information Management, Communicates, Electronic and Automation Control Conference (IMCEC). 4:1947—1950.

Verification code recognition system based on convolutional neural network. In order to strengthen the network security defense work, this paper proposes a novel verification code recognition system based on convolutional neural network. The system combines Internet technology and big data technology, combined with advanced captcha technology, can prevent hackers from brute force cracking behavior to a certain extent. In addition, the system combines convolutional neural network, which makes the verification code combine numbers and letters, which improves the complexity of the verification code and the security of the user account. Based on this, the system uses threshold segmentation method and projection positioning method to construct an 8-layer convolutional neural network model, which enhances the security of the verification code input link. The research results show that the system can enhance the complexity of captcha, improve the recognition rate of captcha, and improve the security of user accounting.

Sun, Wei.  2021.  Taguard: Exposing the Location of Active Eavesdropper in Passive RFID System. 2021 IEEE International Conference on Pervasive Computing and Communications Workshops and other Affiliated Events (PerCom Workshops). :360—363.

This paper exploits the possibility of exposing the location of active eavesdropper in commodity passive RFID system. Such active eavesdropper can activate the commodity passive RFID tags to achieve data eavesdropping and jamming. In this paper, we show that these active eavesdroppers can be significantly detrimental to the commodity passive RFID system on RFID data security and system feasibility. We believe that the best way to defeat the active eavesdropper in the commodity passive RFID system is to expose the location of the active eavesdropper and kick it out. To do so, we need to localize the active eavesdropper. However, we cannot extract the channel from the active eavesdropper, since we do not know what the active eavesdropper's transmission and the interference from the tag's backscattered signals. So, we propose an approach to mitigate the tag's interference and cancel out the active eavesdropper's transmission to obtain the subtraction-and-division features, which will be used as the input of the machine learning model to predict the location of active eavesdropper. Our preliminary results show the average accuracy of 96% for predicting the active eavesdropper's position in four grids of the surveillance plane.