Improving confidentiality is a main concern in most wireless transmission systems. Traditionally, confidentiality is guaranteed by means of encryption, where transmitted data are encrypted prior to transmission and only the intended receiver(s) can decrypt them. However, encryption/decryption process involves high complexity and heavy signaling in the key distribution/agreement protocols. Thus, aiming toward overcoming complexity, physical-layer security has been proposed as a promising candidate to improve confidentiality against eavesdroppers by exploiting physical-layer techniques. In this paper, we propose a physical-layer security scheme that adapts the modulation type based on the channel phase in order to secure the transmitted data. Moreover, the phase of the transmitted signal is adjusted in order to improve the immunity against eavesdroppers. The proposed scheme has been designed to achieve high robustness against channel estimation errors. The performance of the proposed scheme is evaluated through analysis and simulations in order to demonstrate the significant improvement in the confidentiality.
Improving confidentiality is a main concern in most wireless transmission systems. Traditionally, confidentiality is guaranteed by means of encryption, where transmitted data are encrypted prior to transmission and only the intended receiver(s) can decrypt them. However, encryption/decryption process involves high complexity and heavy signaling in the key distribution/agreement protocols. Thus, aiming toward overcoming complexity, physical-layer security has been proposed as a promising candidate to improve confidentiality against eavesdroppers by exploiting physical-layer techniques. In this paper, we propose a physical-layer security scheme that adapts the modulation type based on the channel phase in order to secure the transmitted data. Moreover, the phase of the transmitted signal is adjusted in order to improve the immunity against eavesdroppers. The proposed scheme has been designed to achieve high robustness against channel estimation errors. The performance of the proposed scheme is evaluated through analysis and simulations in order to demonstrate the significant improvement in the confidentiality.
Enhanced confidentiality is a major concern for most communication fields including personal, military, and governmental applications. Conventionally, confidentiality is guaranteed by encryption and corresponding decryption so that the encrypted data can only be decrypted by intended receivers. However, both encryption and decryption processes include high complexity and heavy signaling overhead due to key distribution and agreement protocol. Thus, in order to overcome high complexity and heavy signaling, the Physical Layer Security (PLS) has been proposed as a prospective solution to enhance confidentiality against eavesdroppers by physical layer techniques. This paper proposes a novel physical layer security technique that adopts the Adaptive and Rotated Transmission (ART) scheme based on the instantaneous channel information, i.e., magnitude and channel phase in order to achieve secure transmission. The performance of our proposed transmission scheme is evaluated through mathematical analysis and numerical results, showing a meaningful improvement in confidentiality.
Establishing secured communication among the intended users of wireless networks is a major concern. Especially, providing confidentiality is a critical requirement in a wireless communication system which is more susceptible to eavesdroppers. Prevailing cryptographic methods were proven to meet the security needs to some extent. Sophisticated encryption techniques cannot be always deployed in wireless devices, where the resources are limited. However, physical layer security is recently emerging into a promising paradigm to aid security in wireless networks by exploiting the dynamics of wireless channel. In this study, a physical layer security technique was proposed to enhance confidentiality which selects the modulation type adaptively, based on both channel signal‐to‐noise ratio and phase between transmitter and receiver. The performance of the proposed technique is evaluated for two types of eavesdroppers such as random and intelligent attackers through simulations. The proposed method improves confidentiality and throughput while maintaining the targeted symbol error rate than the existing algorithms.
In this paper, a hybrid scheme to provide wireless physical layer security based on encryption and wireless channel pre-compensation is presented. The physical layer security is provided by converting the signal constellation into a higher order constellation by using conventional encryption (symmetric key encryption) and then using channel state information (i.e. amplitude and phase variation), which is location specific, to further encrypt the constellation before transmission. Since detection and demodulation are based upon the known signal constellation, which is not known in advance in our case, it becomes difficult for the eavesdropper to determine the original signal constellation. The data intercepted by the eavesdropper is unintelligible due to the combined effect of encryption and pre-compensation. Using bit error rate (BER) as performance metric, it is found that the eavesdropper suffers from high BER as compared to its legitimate counterpart hence providing secure communication. The developed scheme was tested with existing wireless communication standard IEEE 802.11 to show the practical application of the scheme.
Physical layer security (PLS) has emerged as a new concept and powerful alternative that can complement and may even replace encryption-based approaches, which entail many hurdles and practical problems for future wireless systems. The basic idea of PLS is to exploit the characteristics of the wireless channel and its impairments including noise, fading, interference, dispersion, diversity, etc. in order to ensure the ability of the intended user to successfully perform data decoding while preventing eavesdroppers from doing so. Thus, the main design goal of PLS is to increase the performance difference between the link of the legitimate receiver and that of the eavesdropper by using well-designed transmission schemes. In this survey, we propose a conceptual, generic, and expandable framework for classifying the existing PLS techniques against wireless passive eavesdropping. In this flexible framework, the security techniques that we comprehensively review in this treatise are divided into two primary approaches: signal-to-interference-plus-noise ratio-based approach and complexity-based approach. The first approach is classified into three major categories: first, secrecy channel codes-based schemes; second, security techniques based on channel adaptation; third, schemes based on injecting interfering artificial (noise/jamming) signals along with the transmitted information signals. The second approach (complexity-based), which is associated with the mechanisms of extracting secret sequences from the shared channel, is classified into two main categories based on which layer the secret sequence obtained by channel quantization is applied on. The techniques belonging to each one of these categories are divided and classified into three main signal domains: time, frequency and space. For each one of these domains, several examples are given and illustrated along with the review of the state-of-the-art security advances in each domain. Moreover, the advantages and disadvantages of each approach alongside the lessons learned from existing research works are stated and discussed. The recent applications of PLS techniques to different emerging communication systems such as visible light communication, body area network, power line communication, Internet of Things, smart grid, mm-Wave, cognitive radio, vehicular ad-hoc network, unmanned aerial vehicle, ultra-wideband, device-to-device, radio-frequency identification, index modulation, and 5G non-orthogonal multiple access based-systems, are also reviewed and discussed. The paper is concluded with recommendations and future research directions for designing robust, efficient and strong security methods for current and future wireless systems.
Security is a critical concern in wireless network. Physical layer security exploits the physical characteristics of wireless channel for secure transmission. The physical layer security approach is a competitive alternative to achieve information-theoretic secrecy. In the area of physical layer security which guarantees confidentiality by using Automatic Repeat Request technique, ARQ is described in a general way that includes its use over a wide range of underlying physical medium. Physical layer security focuses on exploiting the physical layer properties of the wireless channels to protect the confidential information transmission against eavesdropping. It describes the electric or optical signals used for communicating between two computers. Here a physical layer security technique is adopted for secret key distribution. In this improving physical layer based security for wireless network using jamming technique in automatic repeat request has been implemented. The automatic repeat request (ARQ) mechanism is a well-known technique to handle transmission errors, when data is transmitted over noisy channels. This service describes sending and receiving information with possible confirmation. The result obtained gives the performance of the increased signal to noise ratio and the decreased bit error rate and the mean square error.
This letter proposes a receiver-originated physical-layer secure transmissions scheme (ROST) which consists of two-phase communications. In phase 1, the receiver sends a pseudorandom signal (only known by itself) to the transmitter and in phase 2, the transmitter directly sends out the mixture of its confidential message and the received pseudorandom signal. The receiver could estimate the channel with the help of the pseudorandom signal before cancelling it from the received mixed signal, and finally detect the confidential information. By contrast, the eavesdropper can hardly obtain any confidential information because it cannot estimate the channel without any pilot signal in both phases transmissions and is interfered by the pseudorandom signal. Furthermore, we discuss the secrecy capacity of ROST and show that ROST can always keep the security of the confidential message, achieve much higher secrecy capacity than the traditional scheme, even without any channel information at the transmitter.