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In the recent era of computational technologies, the internet is needed daily. The data generated is enormous and primarily stored on dedicated servers or clouds. Data migration and transfer are significant tasks for maintaining consistency and updating data. The data is the most critical component in any cloud service. There are various methods to protect data, like secure transfer, encryption, and authentication. These techniques are used as per need and transmission of the data. As data grows on a server or cloud, it must be migrated securely. Here, the exhaustive survey is provided for building a framework for migrating and transmitting cloud data. The framework should be sustainable and adaptable for load-balancing recovery and secure transmission. Various security load balancing parameters must be considered to obtain these state-of-the-art functionalities in the framework. The existing similar frameworks are studied, and findings are proposed in the paper to develop the framework. [ABSTRACT FROM AUTHOR]

The automatic collection of power grid situation information, along with real-time multimedia interaction between the front and back ends during the accident handling process, has generated a massive amount of power grid data. While wireless communication offers a convenient channel for grid terminal access and data transmission, it is important to note that the bandwidth of wireless communication is limited. Additionally, the broadcast nature of wireless transmission raises concerns about the potential for unauthorized eavesdropping during data transmission. To address these challenges and achieve reliable, secure, and real-time transmission of power grid data, an intelligent security transmission strategy with sensor-transmission-computing linkage is proposed in this paper. The primary objective of this strategy is to maximize the confidentiality capacity of the system. To tackle this, an optimization problem is formulated, taking into consideration interruption probability and interception probability as constraints. To efficiently solve this optimization problem, a low-complexity algorithm rooted in deep reinforcement learning is designed, which aims to derive a suboptimal solution for the problem at hand. Ultimately, through simulation results, the validity of the proposed strategy in guaranteed communication security, stability, and timeliness is substantiated. The results confirm that the proposed intelligent security transmission strategy significantly contributes to the safeguarding of communication integrity, system stability, and timely data delivery. [ABSTRACT FROM AUTHOR]

Wireless Network security management is difficult because of the ever-increasing number of wireless network malfunctions, vulnerabilities, and assaults. Complex security systems, such as Intrusion Detection Systems (IDS), are essential due to the limitations of simpler security measures, such as cryptography and firewalls. Due to their compact nature and low energy reserves, wireless networks present a significant challenge for security procedures. The features of small cells can cause threats to the network. Network Coding (NC) enabled small cells are vulnerable to various types of attacks. Avoiding attacks and performing secure "peer" to "peer" data transmission is a challenging task in small cells. Due to the low power and memory requirements of the proposed model, it is well suited to use with constrained small cells. An attacker cannot change the contents of data and generate a new Hashed Homomorphic Message Authentication Code (HHMAC) hash between transmissions since the HMAC function is generated using the shared secret. In this research, a chaotic sequence mapping based low overhead 1D Improved Logistic Map is used to secure "peer" to "peer" data transmission model using lightweight H-MAC (1D-LM-P2P-LHHMAC) is proposed with accurate intrusion detection. The proposed model is evaluated with the traditional models by considering various evaluation metrics like Vector Set Generation Accuracy Levels, Key Pair Generation Time Levels, Chaotic Map Accuracy Levels, Intrusion Detection Accuracy Levels, and the results represent that the proposed model performance in chaotic map accuracy level is 98% and intrusion detection is 98.2%. The proposed model is compared with the traditional models and the results represent that the proposed model secure data transmission levels are high. [ABSTRACT FROM AUTHOR]

Abstract The authors propose a secure intelligent reflecting surface (IRS) assisted transmission system in the presence of a ground eavesdropper, where the source in the ground transmits confidential information to unmanned aerial vehicle (UAV), IRS is deployed to promote the transmission rate of the source to UAV. Closed‐form expression for secure transmission non‐outage probability is derived, and secure transmission performance is analyzed. Simulation validates the correctness of the derivation. Compared with benchmarks, results show that the IRS can improve the secure transmission of ground to UAV.

Patients' medical data are extremely sensitive information during storage and transfer, and it needs the highest security level. Furthermore, these records must frequently be linked to patient medical data, and then the linked medical data are securely transmitted to the healthcare center. In this study, a Blockchain-Based Traceable Data Sharing method is proposed to securely transfer the medical data. A Paillier homomorphic encryption method is used to prevent data theft or attacks from occurring in the cloud as a result of the transfer of medical data there. It prevents intravenous third parties, which executes arithmetic operations on the ciphertext. Then the encrypted data are stored in the cloud and to remove clone nodes in the gateway, a software-defined networking technology is introduced. Then a Blockchain-Based Traceable Data Sharing is proposed to ensure data privacy and authenticity while maintaining data privacy at the point of data transmission. Data are then encrypted using a new Enhanced Cipher Text-Policy Encryption Attribute-based Encryption (E-CP-ABE). Private blockchain transfers are carried out on the chain, supporting fine-grain access control with flexible access policies and creating a private key in E-CP-ABE. The presented technique is executed in Matlab software of version R2020a. The performance parameters are encryption, and decryption time, mean square error (MSE), peak signal-to-noise ratio (PSNR), sensitivity, respectively. The encryption process function is nearly 8% superior than the existing methods and the decryption time is 14% greater than other methods. As a result, this study shows that the research approach outperformed in terms of encryption time and decryption time, as well as PSNR, MSE, and sensitivity. This technique outperforms other state-of-the-art algorithms in terms of imperceptibility and robustness against various attacks. Consequently, this approach is more reliable than previous methods for the transmission of medical data. [ABSTRACT FROM AUTHOR]

The approach to ensuring secure transmission in a mobile Ad hoc network (MANET) involves safeguarding the information exchanged between devices. It involves using encryption and authentication techniques to make sure that only authorized devices can access the data and that the data remains unchanged and trustworthy. However, implementing secure broadcasting can be challenging due to factors like limited resources, the dynamic nature of networks, and trust management. To overcome those issues, the trust-based multi-objective-pelican optimization algorithm (TMO-POA) method is used in this paper to offer great security for the data packets and stop malevolent attacks. The energy efficacy of the node and trust values are evaluated. The superior cluster head is selected for that TMO-POA appraisal of the cost function. Let's detect the malevolent node in the network, decrease the packet loss, and evaluate the trust value of the node in its neighbourhood. Upgrading the routing detail is made easier by the trust value and maximizes the network throughput. The outcomes attained from the simulation show that the suggested TMO-POA succeeded in excellent execution according to various parameters metrics. From the results, the proposed TMO-POA, succeeded in achieving maximum throughput (550.01 Kbps), Average energy consumption (0.90J), routing overhead (0.0550), PDR (0.999) and delay (11.23ms), which is much better than the existing bacteria foraging optimization algorithm (BFOA), cat slapped solo algorithm (C-SSA), and trust-based efficiency routing (TER) algorithms. [ABSTRACT FROM AUTHOR]

The authors propose a secure intelligent reflecting surface (IRS) assisted transmission system in the presence of a ground eavesdropper, where the source in the ground transmits confidential information to unmanned aerial vehicle (UAV), IRS is deployed to promote the transmission rate of the source to UAV. Closed‐form expression for secure transmission non‐outage probability is derived, and secure transmission performance is analyzed. Simulation validates the correctness of the derivation. Compared with benchmarks, results show that the IRS can improve the secure transmission of ground to UAV. [ABSTRACT FROM AUTHOR]

The sixth generation (6G) of cellular transmission is extremely adaptable. 6G will equip everyone with pervasive wireless connectivity and meet the needs of a fully connected world. It is anticipated that revolutionary ideas will increase in support for a fast-expanding variety of smart devices and applications. The sophisticated characteristics of 5G portable cellular network infrastructures produce novel threats and requirements. Comparing 6G cellular network technologies to 5G cellular networks, this paper discusses various security and privacy issues in 6G cellular networks based numerous security services. Proposes AA approach to evaluate the effectiveness of the methodology. Propose a new 6G wireless security architecture based on the analysis of secret key authentication and flexible position based identification, which serves as the foundation for an examination of identity management and flexible authentication. Demonstrates the benefits of the proposed architecture, analyzes BER against SINR and Measure Throughput Against various SINR values. Finally, Limitations and future recommendation for 6G cellular network security is presented.

With the development of Cyber-Physical Systems (CPSs), many industrial facilities have realized remote control and monitoring. However, the widespread of CPSs has brought new issues and challenges in terms of security. Attackers can exploit vulnerabilities induced by network communication, tamper with transmitted data, and cause serious accidents through carefully designed covert attacks. This paper proposes a residual-driven comprehensive defense scheme based on the coprime factorization technique to address the threat posed by concealed CPS attacks. The novel scheme protects CPS from stealth cyber-physical attacks through secure transmission and attack detection. In particular, a secure transmission method is first introduced to prevent information leakage from the source. The pivotal idea is to convert confidential transmission control and measurement signals into non-essential filtered residual signals. It contributes to the reduction of information leakage and helps reduce the risks of stealth attacks. Then, under the same residual-driven framework, a stealth attack detection approach is put forward. It can eliminate false alarms caused by system faults, and therefore, achieve superior efficacy in detection accuracy under stealth attacks. Finally, simulation research is conducted on the F-404 engine to verify the effectiveness and performance of the proposed scheme and approach. [ABSTRACT FROM AUTHOR]

Tele radiology plays a significant role in medicine that allows secure transmission of medical imaging data over a wide range of communication network. It guarantees data reliability and enables convenient way of communication for diagnostic purposes and clinical interpretation. However it raises the issue of legal, privacy, ethical issue and other copyright authenticity. Hence security and privacy remains to be a predominant problem in the medical field. To address this issue the present study has been motivated by the concept of watermarking schemes. Improved tele radiology architecture was developed in this study with efficient watermarking scheme that incorporates the integrated activity of biometrics and cryptography. In accordance to the entropy model, the fingerprint feature obtained from DICOM image is retrieved for key generation. 2L-DWT and TT-OA algorithm is employed to obtain high efficiencywith respect to PSNR (77 dB), 121s of encryption, SSIM (0.99), and embedding efficiency (97%). [ABSTRACT FROM AUTHOR]

Due to the excellent broadcasting characteristics of radio signals, simultaneous wireless information and power transfer (SWIPT) can transmit both information and energy, and provide users with stable power supply. Wireless channel has the characteristics of openness, which will lead to the leakage of information in the SWIPT system. It is one of the research hotspots in the industry to ensure the secure transmission of information in SWIPT system where there are differences in the transmission of energy and information. This paper proposes an ‘information-energy’ dynamic switching opportunistic secure transmission scheme. First, a model considering three factors of multi-cell, multi-user and multiple eavesdropper is established which assumes that the user adopts a time-domain switching receiver that collects energy in a nonlinear model. Then, combined with the time-varying wireless channel, a dynamic information energy switching transmission scheme based on signal-to-interference noise ratio threshold is proposed. Finally, the energy and information transmission performance of the scheme are comprehensively analysed.

The Internet of Things, as an important part of important data aggregation, forwarding and control, is often subject to risks such as eavesdropping or data loss due to the huge amount of received data. Based on this, this paper introduces the GA-LM-BP algorithm, BP network, and LM-BP algorithm deep learning to optimize the data received by the Internet of Things, and selects the most suitable communication mode optimization algorithm. The experimental results show that the accuracy error of GA-LM-BP, BP and LM-BP algorithms shows a downward trend, from 0.029 to 0.011; the training time is reduced by 208 mins, and the training speed is increased to 74%, indicating that GA-LM-BP deep learning Excellent performance in the security and confidentiality of data transmission in the Internet of Things. In addition, we further analyzed GA-LM-BP from COP, SOP and STP to verify its reliability and safety.

Cloud computing has encountered accelerated growth and technological advancements in recent times. However, Cloud computing is still perceived to be in its infancy and will unfold its hidden potential by augmenting its services with future technologies like Metaverse, Augmented Reality, and Virtual Reality. The demand for computing resources has also increased with the increase in the number of service users, thus, the data owners outsource their computational demands to the cloud servers configured at remote locations. Since the cloud offers multi-tenancy, the risk for unauthorized access and network attacks like Denial-of-Service attacks, and Sybil attacks, increases due to the consumption of shared resources and hypervisor exploitation. In order to protect the owner's data from unauthorized access, it needs to be encrypted before being outsourced. Conventional cryptosystems decrypt the encoded message before performing computations on the outsourced data, which increases the computational complexity of the system. Homomorphic Encryption permits the cloud service provider to perform computations on encrypted data without the need for decryption. Hence, in this paper, we introduce a layer of secure cipher gateway for user data. This work demonstrates an integrated scheme based on Partial Homomorphic Encryption and Role-Based Access Control policies to restrict unauthorized access. Data access is granted strictly as per the user-role mapping in the role-based hierarchy to ensure data integrity. The proposed model also suggests mitigation techniques for various cloud attacks. The work has been compared with its peers based on a secured communication channel for data transmission with reduced encryption and decryption time. [ABSTRACT FROM AUTHOR]

The visual cryptography scheme (VCS) distributes a secret to several images that can enhance the secure transmission of that secret. Quick response (QR) codes are widespread. VCS can be used to improve their secure transmission. Some schemes recover QR codes with many errors. This paper uses a distribution mechanism to achieve the error-free recovery of QR codes. An error-correction codeword (ECC) is used to divide the QR code into different areas. Every area is a key, and they are distributed to n shares. The loss of any share will make the reconstructed QR code impossible to decode normally. Stacking all shares can recover the secret QR code losslessly. Based on some experiments, the proposed scheme is relatively safe. The proposed scheme can restore a secret QR code without errors, and it is effective and feasible. [ABSTRACT FROM AUTHOR]

In this paper, a novel secure image signal transmission scheme was proposed in wireless systems, in which the poly-polarization filtering and the orthogonal matrix (PPF-OM) were combined to protect the image signal and eliminate the polarization dependent loss (PDL) at the same time, which was caused by the non-ideal wireless channel. This scheme divided the image information sequence into two parts in order to modulate and reshape the results into symbol matrices with the same size. Then, two sets of polarization states (PSs) and orthogonal matrices (OMs) were designed to process the symbols in order to enhance information protection and eliminate the PDL. Legitimate users were able to apply the shared PSs and OMs, step by step, so the information could be recovered. However, for eavesdroppers, the received signals were random symbols that were difficult to demodulate. Then, the bit error rate and the secrecy rate were derived to evaluate the performance of the PPF-OM scheme. Finally, the simulations demonstrated the superior performance of the PPF-OM scheme for enhancing the information security and eliminating the PDL. [ABSTRACT FROM AUTHOR]

The “time” factor in time-modulated arrays (TMAs) offers a new degree of freedom for securing wireless communication. However, the widely used periodic time modulation introduces limited randomness for eavesdropping receivers, and thus gives weak security. To meet this challenge, this work proposes a TMA with chaotic-enabled phase modulation (CPM) for secure transmission. The proposed CPM technique offers the chaos features of high randomness, unpredictability, and initial condition sensitive characteristic, to increase the information uncertainty for eavesdropping receivers. An optimization-based time sequence design approach is introduced to design optimal CPM time sequences for secure transmission in a given direction. Thus, a variety of security strategies including beam scanning, directional modulation (DM), and chaotic encryption are simultaneously enabled by the optimized CPM time sequence. Moreover, the CPM is a radio frequency (RF)-domain security technique without requiring any baseband modulation modules, which exhibits a simplified hardware architecture. Numerical analysis and experimental results are presented to illustrate the effectiveness of the proposed CPM technique. The results indicate that the security is improved by lowering the bit error rate (BER) between the legitimate receiver and the transmitter, and reducing the mutual information between eavesdropping receivers and the transmitter. [ABSTRACT FROM AUTHOR]

Various sensor nodes are interconnected with each other in wireless sensor network (WSN). WSN communicates to every node within the network wirelessly to collect data regarding the surrounding environment and send the particular data to the destination/centralised location. The sensor nodes transmit the data and the source sensor node transmits data to destination sensor nodes through various intermediary sensor nodes. Thus, secure transmission is required in which WSN must be free from malicious nodes to achieve safe transfer. In this paper, our objective is to provide secure data transmission in an efficient manner from source to destination through a trust based path namely novel fuzzy based crow search optimization algorithm (F-CSO) and optimised link state routing protocol (OLSR) protocol. Through NS3 tool, nodes are deployed in the network area and novel F-CSO is performed with respect to three parameters such as distance, degree and transmission energy. The best nodes are considered for optimization process and it must satisfy the three conditions such as lower distance between each node for transmitting the data, higher degree and higher energy for transmission. A set of nodes that satisfies this condition are gathered by the fuzzy rule technique and then further optimised by crow search optimization technique leading to exact nodes through which trust based transmissions are performed. Further, routing can be achieved by the OLSR protocol. The performance of the proposed system is compared with existing studies with respect to the system for detecting the malicious nodes with and without utilizing proposed F-CSO in terms of execution time, throughput, and packet delivery ratio. The evaluation result has shown that malicious nodes is detected in an efficient manner through the use of F-CSO, showing better results with various parameters. [ABSTRACT FROM AUTHOR]

With the aim of ensuring secure transmission in high-mobility wireless scenarios, this paper proposes a 2D permutation-aided Orthogonal Time Frequency Space (OTFS) secure transmission scheme, which uses the Gosudarstvennyi Standard (GOST) algorithm to perform disturbance control on the OTFS modulation domain. Furthermore, we develop an improved SeLective Mapping (SLM) algorithm, which can significantly improve the Peak-to-Average Power Ratio (PAPR) problem with very low complexity. In addition, we carry out the security analysis, investigating the proposed scheme's resistance performance to a range of effective attacks. Finally, our numerical results show that our proposed transmission scheme can guarantee the underlying security property of OTFS. [ABSTRACT FROM AUTHOR]

In real communication systems, secure and low-energy transmit scheme is very important. So far, most of schemes focus on secure transmit in special scenarios. In this paper, our goal is to propose a secure protocol in wireless networks involved various factors including artificial noise (AN), the imperfect receiver and imperfect channel state information (CSI) of eavesdropper, weight of beamforming (BF) vector, cooperative jammers (CJ), multiple receivers, and multiple eavesdroppers, and the analysis shows that the protocol can reduce the transmission power, and at the same time the safe reachability rate is greater than our pre-defined value, and the analysis results are in good agreement with the simulation results. In this letter, the minimal transmit power is modeled as a non-convexity optimization that is general difficult. Our method is to transform it into a two-level non-convex problem. The outer is a univariate optimization that can be solved by the golden search algorithm. The inner is a convex optimization solved by using the CVX. The solutions are further used to improve the confidentiality rate of the system, and reduce the transmit power of the system and resource consumption in terms of the imperfect CSI. Simulations show the efficiency and robustness of the proposed protocol. [ABSTRACT FROM AUTHOR]

The paper presents analysis of the possibility of using selected hash functions submitted for the SHA-3 competition in the SDEx encryption method. The group of these functions will include the finalists of the SHA-3 competition, i.e. BLAKE, Grøstl, JH, Keccak, Skein. The aim of the analysis is to develop more secure and faster cryptographic algorithm compared to the current version of the SDEx method with SHA- 512 and the AES algorithm. When considering the speed of algorithms, mainly the software implementation will be taken into account, as it is the most commonly used.

A novel optical frequency-hopping (OFH) scheme using dual-drive Mach-Zehnder modulator (DD-MZM) is proposed and demonstrated for secure transmission in fiber-optic networks. In the proposed scheme, by adjusting the phase difference between the radio frequency (RF) signals loaded on the two arms of the DD-MZM, and filtering the center carrier by fiber Bragg grating (FBG), thus the upper and lower output spectra can be realized randomly hop between the positive and negative first-order sidebands and serve as carriers for data modulation. And the data of different users are divided into many data slices in the time domain and then modulated to these carriers. To verify the feasibility of the proposed OFH scheme, we demonstrate an error-free transmission through 40 km fiber with 10 Gbps hopping rate and 10 Gbps data rate by simulation tools. In addition, we also establish a theoretical model to evaluate the security performance quantitatively, and the results show that the computing power required by illegal third parties to crack through brute force reaches 1.07 × 1027 calculations per second under certain conditions, which is almost impossible. Our OFH scheme has provided a deeper insight into physical layer security.

The electronic transmission of radiographic images from one geographical location to another location is known as teleradiology. Radiological image processing issues occurred during the transmission across various medical image workstations have been handled by this approach, in order to provide various health care activities. (i.e., diagnosis, medical practicing, consulting second opinion, or treatment and monitor a patient). The major difficulties of remote transmission process are privacy, safety, image retention, etc. A noise‐tolerant signal is being implanted with a digital watermark furtively (e.g., an image, symbol, audio, video, etc.), concerning the typical identification of the signal's patent. The intention of utilizing digital watermarks is either to validate the carrier signal's authenticity and ethics or to reveal its patent holder's identity, to provide protected transmission. In this work, watermarking approach is implemented to integrate biometrics with cryptography. The entropy‐based fingerprint feature has been extracted for generating the key to process the cryptography, and digital imaging and communications in medicine (DICOM) images. To obtain secure transmission, two‐level discrete wavelet transform method is employed for watermarking the cover image with encrypted image. Subsequently, the receiver can extract the watermarked image by using watermarking keys. This method is proposed to access the diagnostic image with privacy, accessibility, and reliability. The anticipated outputs of the proposed approach have been assessed based on factors such as structural similarity index measures (SSIM), normalized correlations (NC), and peak‐signal‐to‐noise ratio (PSNR). [ABSTRACT FROM AUTHOR]

A direction-range-time dependent vortex wave directional modulation (DM) scheme based on the frequency diverse array (FDA) is proposed for secure transmission. We design the random frequency offset for the array element in a circular arc FDA, which generates the quasi-helical phase front and the irregular phase front at the specific range. In order that the time-variance phase front can maintain the helical phase characteristics at the desired range, according to the designed frequency offset function, we design a DM excitation signal with the specific time-variance phase offset for each array element. The direction-range-time dependent phase pattern is modulated into the vortex signal constellation for the desired transmission. Theoretical analyses and numerical simulations validate the effectiveness of our proposed approach with no artificial noise. [ABSTRACT FROM AUTHOR]

Abstract Mobile edge computing can provide short-range cloud computing capability for the mobile users, which is considered to be a promising technology in 5G communication. The mobile users offload some computing tasks to the edge server through the wireless backhaul link, which can reduce the energy consumption and the time latency. Meanwhile, due to the open characteristics of the wireless channel, the offloading tasks through the backhaul link may face the risk of eavesdropping. Therefore, the secure transmission based on physical layer security for the offloading tasks to the edge server is considered. The optimization problem of minimizing the energy consumption for the vehicular stations (VSs) in mobile edge computing-assisted high-speed railway communication system is studied in this paper. The energy consumption of the mobile users is generated by executing the local computing task and by transmitting the partial offloading task to the edge server. In this paper, a novel joint iterative optimization algorithm is proposed. By jointly optimizing the task scheduling, the task offloading and the transmission power, the energy consumption of all VSs is minimized under the constraint of the time latency. Numerical simulation results verify the effectiveness of the proposed algorithm.

In 6G-oriented vehicular Internet of things (IoT) services, the integration of a low altitude platform (LAP) and intelligent reflecting surfaces (IRS) provides a promising solution to achieve seamless coverage and massive connections at low cost. However, due to the open nature of wireless channels, how to protect the transmission of privacy information in LAP-based IRS symbiotic vehicular networks remains a challenge. Motivated by the above, this paper investigates the LAP and IRS enhanced secure transmission problem in the presence of an eavesdropper. Specifically, we first deploy a fixed LAP equipped with IRS to overcome the blockages and introduce artificial noise against the eavesdropper. Next, we formulate a total secure channel capacity maximization problem by optimizing the phase shift, power distribution coefficient, and channel allocation. To effectively solve the formulated problem, we design an iterative algorithm with polynomial complexity, where the optimization variables are solved in turn. In addition, the complexity and convergence of the proposed iterative algorithm are analyzed theoretically. Finally, numerical results show that our proposed secure transmission scheme outperforms the comparison schemes in terms of the total secure channel capacity.

The visual cryptography scheme (VCS) distributes a secret to several images that can enhance the secure transmission of that secret. Quick response (QR) codes are widespread. VCS can be used to improve their secure transmission. Some schemes recover QR codes with many errors. This paper uses a distribution mechanism to achieve the error-free recovery of QR codes. An error-correction codeword (ECC) is used to divide the QR code into different areas. Every area is a key, and they are distributed to n shares. The loss of any share will make the reconstructed QR code impossible to decode normally. Stacking all shares can recover the secret QR code losslessly. Based on some experiments, the proposed scheme is relatively safe. The proposed scheme can restore a secret QR code without errors, and it is effective and feasible.

Abstract In this paper, the secure transmission for high-speed railway (HSR) communication system is studied. The considered HSR wireless communication system consists of a macro base station, B roadside base stations, and K vehicle stations (VSs) on the top of the train, and the eavesdropping user is a mobile unmanned aerial vehicle (UAV). We consider maximizing the sum of the minimum security rate of each time slot as the objective function, and the constraint conditions contain the quality of service (QoS), switch requirements and the total power constraint. The original optimization problem is mixed-integer and non-convex, it is intractable to solve directly. The block coordinate descent (BCD) method is applied, and the original problem can be decoupled into two sub-problems. The one is the joint BS-VS association problem, and the other is the power control problem. The first sub-problem of optimizing BS-VS association can be solved by the successive convex approximation (SCA) algorithm, and the second one of optimizing transmit power can be solved by the lagrangian dual method. Simulation results show that the proposed algorithms have good convergence.

Non-orthogonal unmanned aerial vehicle (UAV)-aided secure downlink transmissions are investigated. A single-antenna UAV serves multiple ground users in the face of multiple colluding eavesdroppers (EVs) and only imperfect location information of the EVs is available. Specially, a power splitting based secure non-orthogonal downlink transmission scheme is considered, where the transmit power is divided into two parts for transmitting confidential information and artificial noise. Explicitly, we maximize the minimum average secrecy rate among all the users by optimizing the UAV trajectory, the transmit power and the power splitting ratio. In order to tackle this non-convex optimization problem, we propose an iterative algorithm based on the block coordinate descent and successive convex approximation techniques. Numerical results demonstrate the superiority of our proposed algorithm. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the secure vehicle communications in cybertwin-enabled integrated satellite-terrestrial networks, where the digital twins (DTs) in the cybertwin space reflects the physical entities (i.e., satellite, terrestrial base station (BS), and vehicles). Particularly, considering the channel similarity between different satellite links versus the randomness difference in terrestrial links, it is challenging to reach the secure transmission in satellite and terrestrial links independently with limited resources. Considering the information exchange in the cybertwin space can support an information sharing between such physical entities, the secure transmission design by using the heterogeneous satellite-terrestrial resources can be conducted from a global perspective. With the channel feedback information of vehicles gathered at the cybertwin, the co-channel interference caused by the spectrum sharing is leveraged to assist the implementation of secure transmissions in the integrated satellite-terrestrial vehicle network. Specifically, the problems of maximizing the secrecy rate of satellite-to-vehicle link and the terrestrial BS-to-vehicle link are formulated, respectively. To solve such two problems, we propose two corresponding beamforming optimization approaches, where semi-definite relaxation (SDR) and semi-definite programming (SDP) are adopted due to the non-convexity. In addition, the tightness of SDR is proved and the complexity of proposed approaches is also analyzed. Finally, extensive numerical simulations are carried out and results show the effectiveness of our proposed approach. [ABSTRACT FROM AUTHOR]

We demonstrate a new approach to implementing directional modulation that leverages distributed array dynamics to change the antenna array pattern over time. With appreciable spacing between the elements, the spatial phase pattern varies rapidly, such that small physical motions result in large phase variations. We define an average radiation pattern that characterizes the space–time modulation of the array pattern and calculate a spatial information filter based on the additional modulation imparted on transmitted data. The concept is demonstrated experimentally using a two-element 1.5 GHz transmit array with relative motion between the elements. The array consists of two nodes, each with one dipole antenna transmitting BPSK data, and each with two log-periodic antennas used to estimate the relative separation of the nodes and correct the beamsteering phase of the transmitters. The node separation is varied dynamically over a range of $0.98\lambda $ – $4.7\lambda $. We investigate the use of linearly and sinusoidally varying internode dynamics, and demonstrate a low bit-error-ratio of approximately 10−5 at the desired transmission direction, indicating high throughput, and a high error ratio of approximately 10−0.3 at angles outside of the mainbeam, indicating corrupted data, at a signal-to-noise ratio of 12 dB. [ABSTRACT FROM AUTHOR]

This paper investigates the secure transmission in downlink cell-free massive multiple-input multiple-output (MIMO) systems in the presence of an active multi-antenna eavesdropper (Eve) over Rician fading channels, assuming that each access point (AP) possesses multiple antennas which are connected with low-resolution digital-to-analog converters (DACs). Closed-form expressions of the achievable secrecy rate relied on the additive quantization noise model are derived. Based on these analytical results, we quantify the impacts of key system parameters, such as the antenna array number, DAC resolution, Rician $\mathcal K$ -factor, and balance factor between data and artificial noise power on secrecy enhancement. Several interesting insights are attained by assuming that Eve can or cannot perfectly remove inter-mobile-terminal interference. Moreover, we also propose a power control algorithm that maximizes the achievable secrecy rate, which can be represented as a series of second-order-cone programs for which efficient solvers exist. All the theoretical analyses and the effectiveness of the proposed algorithm are corroborated by simulation experiments. [ABSTRACT FROM AUTHOR]

With the maneuverability and mobility control of unmanned aerial vehicle (UAV), carrying mobile edge computing (MEC) servers on UAVs is able to effectively alleviate the explosive growth of data traffic pressure. However, UAV adopts line-of-sight transmission which has broadcasting characteristics. Malicious eavesdroppers can easily take advantage of the characteristics to eavesdrop information during the UAV edge computing. Therefore, the security of the UAV-MEC systems is a challenging problem. This article proposes a secure communication scheme for the dual-UAV-MEC system. In the proposed scheme, UAV server assists ground users in calculating the offloading tasks. In order to reduce the eavesdropping of offloading information by UAV eavesdropper, jammer sends interference signals on the ground. We aim to maximize the user's minimum secure calculation capacity by optimizing resources and trajectory of the UAV server. We first transform the optimization problem into a tractable form through mathematical methods and use successive convex approximation and block coordinate descent algorithms to solve it in an iterative manner. The final numerical results show that, compared with the benchmark schemes, the method proposed in this article effectively increases the secure calculation capacity of the system. [ABSTRACT FROM AUTHOR]

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Data is the last defense line of security, in order to prevent data loss, no matter where the data is stored, copied or transmitted, it is necessary to accurately detect the data type, and further clarify the form and encryption structure of the data transmission process to ensure the accuracy of the data, so as to prevent data leakage, take the data characteristics as the core, use transparent encryption and decryption technology as the leading, and According to the data element characteristics such as identity authentication, authority management, outgoing management, file audit and external device management, the terminal data is marked with attributes to form a data leakage prevention module with data function, so as to control the data in the whole life cycle from creation, storage, transmission, use to destruction, no matter whether the data is stored in the server, PC or mobile device, provide unified policy management, form ecological data chain with vital characteristics, and provide comprehensive protection system for file dynamic encryption transmission, such as prevention in advance, control in the event, and audit after the event, so as to ensure the security of dynamic encryption in the process of file transmission, ensure the core data of the file, and help the enterprise keep away from the risk of data leakage. [ABSTRACT FROM AUTHOR]

In this paper, a novel secure image signal transmission scheme was proposed in wireless systems, in which the poly-polarization filtering and the orthogonal matrix (PPF-OM) were combined to protect the image signal and eliminate the polarization dependent loss (PDL) at the same time, which was caused by the non-ideal wireless channel. This scheme divided the image information sequence into two parts in order to modulate and reshape the results into symbol matrices with the same size. Then, two sets of polarization states (PSs) and orthogonal matrices (OMs) were designed to process the symbols in order to enhance information protection and eliminate the PDL. Legitimate users were able to apply the shared PSs and OMs, step by step, so the information could be recovered. However, for eavesdroppers, the received signals were random symbols that were difficult to demodulate. Then, the bit error rate and the secrecy rate were derived to evaluate the performance of the PPF-OM scheme. Finally, the simulations demonstrated the superior performance of the PPF-OM scheme for enhancing the information security and eliminating the PDL.

Despite the wide utilization of unmanned aerial vehicles (UAVs), UAV communications are susceptible to eavesdropping due to air-ground line-of-sight channels. Intelligent reflecting surface (IRS) is capable of reconfiguring the propagation environment, and thus is an attractive solution for integrating with UAV to facilitate the security in wireless networks. In this paper, we investigate the secure transmission design for an IRS-assisted UAV network in the presence of an eavesdropper. With the aim at maximizing the average secrecy rate, the trajectory of UAV, the transmit beamforming, and the phase shift of IRS are jointly optimized. To address this sophisticated problem, we decompose it into three sub-problems and resort to an iterative algorithm to solve them alternately. First, we derive the closed-form solution to the active beamforming. Then, with the optimal transmit beamforming, the passive beamforming optimization problem of fractional programming is transformed into corresponding parametric sub-problems. Moreover, the successive convex approximation is applied to deal with the non-convex UAV trajectory optimization problem by reformulating a convex problem which serves as a lower bound for the original one. Simulation results validate the effectiveness of the proposed scheme and the performance improvement achieved by the joint trajectory and beamforming design. [ABSTRACT FROM AUTHOR]

The paper presents analysis of the possibility of using selected hash functions submitted for the SHA-3 competition in the SDEx encryption method. The group of these functions will include the finalists of the SHA-3 competition, i.e. BLAKE, Grøstl, JH, Keccak, Skein. The aim of the analysis is to develop more secure and faster cryptographic algorithm compared to the current version of the SDEx method with SHA- 512 and the AES algorithm. When considering the speed of algorithms, mainly the software implementation will be taken into account, as it is the most commonly used. [ABSTRACT FROM AUTHOR]

The circular phased array is one of the main methods to generate radio frequency orbital angular momentum (RF-OAM) beams with high purity and capability of OAM-beams steering, but OAM beams generation and steering are only related to angle, not range dimensions. Therefore, the mode of OAM beams can be easily received in a wide range and intercepted by unintended eavesdroppers in the beam axis. As a promising solution, a range-angle dependent OAM beams transmission scheme is highlighted by the frequency diverse array (FDA) for the sake of the OAM secure transmission in this paper. In order to realize the range-angle dependent OAM beams, a special frequency interval between adjacent antenna elements in the FDA is designed and illustrated. The modes of OAM beams generated by the FDA can only be observed in the legal target location. Numerical results show that the scheme can effectively realize the safe transmission of OAM beams, i.e., reducing the possibility of the OAM beams being tapped, improving the OAM-beams transmission performance, and enhancing the energy efficiency with low complexity.

With the increasing demands in modern communications, the concepts of energy-efficient and low-cost processors have received a lot of attention from researchers in recent years. These cases are also taken into consideration in today's high-speed and high-capacity communications (HSHCC), which is one of the requirements in new generation of wireless networks i.e., 6G. International telecommunication union's (ITU) goal in wireless communications is to deliver higher data rates up to 10 Gbps, along with high spectral efficiency and advanced coverage. In multi-gigabit or terabit-per-second wireless communications, digital signal processing (DSP) faces significant challenges. Therefore, analog signal processing (ASP) and design methods based on it have gained a new importance recently. In today's modern telecommunication systems, ASP is used in areas such as the design of analog-to-digital converter (ADC)-less and also DAC-less transceivers, beamforming, secure communication, deep learning (DL), neural network accelerators (ANN), real-time phasers-based applications, Internet of things (IoT), etc. In this research, we describe and classify the works done in this field. This paper presents a comprehensive review of the ASP concept, challenges, and outlooks in modern and smart communications to pave the path for academic and industrial researchers who aim to work in this area. [Display omitted] [ABSTRACT FROM AUTHOR]

Mobile edge computing can provide short-range cloud computing capability for the mobile users, which is considered to be a promising technology in 5G communication. The mobile users offload some computing tasks to the edge server through the wireless backhaul link, which can reduce the energy consumption and the time latency. Meanwhile, due to the open characteristics of the wireless channel, the offloading tasks through the backhaul link may face the risk of eavesdropping. Therefore, the secure transmission based on physical layer security for the offloading tasks to the edge server is considered. The optimization problem of minimizing the energy consumption for the vehicular stations (VSs) in mobile edge computing-assisted high-speed railway communication system is studied in this paper. The energy consumption of the mobile users is generated by executing the local computing task and by transmitting the partial offloading task to the edge server. In this paper, a novel joint iterative optimization algorithm is proposed. By jointly optimizing the task scheduling, the task offloading and the transmission power, the energy consumption of all VSs is minimized under the constraint of the time latency. Numerical simulation results verify the effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]