Due to the enormous spreading of applied wireless networks, security is actually one of the most important issues for telecommunications. One of the main issue in the field of securing wireless information exchanging is the initial common knowledge between source and destination. A shared secret is normally mandatory in order to decide the encryption (algorithm or code or key) of the information stream. It is usual to exchange this common a priori knowledge by using a "secure" channel. Nowadays a secure wireless channel is not possible. In fact normally the common a priori knowledge is already established (but this is not secure) or by using a non-radio channel (that implies a waste of time and resource). This contribution deals with the proposal of a new modulation technique ensuring secure communication in a full wireless environment. The information is modulated, at physical layer, by the thermal noise experienced by the link between two terminals. A loop scheme is designed for unique recovering of mutual information. The probability of error/detection is analytically derived for the legal users and for the third unwanted listener. The proposed scheme has also been implemented in a Xilinx Virtex II FPGA. All the results show that the performance of the proposed scheme yields the advantage of intrinsic security, i.e., the mutual information cannot be physically demodulated (passive attack) or denied (active attack) by a third terminal, leading us to conclude that the proposed technique is really useful for private key distribution in every wireless network.
Due to the enormous spreading of applied wireless networks, security is actually one of the most important issues for telecommunications. One of the main issue in the field of securing wireless information exchanging is the initial common knowledge between source and destination. A shared secret is normally mandatory in order to decide the encryption (algorithm or code or key) of the information stream. It is usual to exchange this common a priori knowledge by using a "secure" channel. Nowadays a secure wireless channel is not possible. In fact normally the common a priori knowledge is already established (but this is not secure) or by using a non-radio channel (that implies a waste of time and resource). This contribution deals with the proposal of a new modulation technique ensuring secure communication in a full wireless environment. The information is modulated, at physical layer, by the thermal noise experienced by the link between two terminals. A loop scheme is designed for unique recovering of mutual information. The probability of error/detection is analytically derived for the legal users and for the third unwanted listener. The proposed scheme has also been implemented in a Xilinx Virtex II FPGA. All the results show that the performance of the proposed scheme yields the advantage of intrinsic security, i.e., the mutual information cannot be physically demodulated (passive attack) or denied (active attack) by a third terminal, leading us to conclude that the proposed technique is really useful for private key distribution in every wireless network.
Due to the enormous spreading of applied wireless networks, security is actually one of the most important issues for telecommunications. One of the main issue in the field of securing wireless information exchanging is the initial common knowledge between source and destination. A shared secret is normally mandatory in order to decide the encryption (algorithm or code or key) of the information stream. It is usual to exchange this common a priori knowledge by using a “secure” channel. A new modulation technique, able to encrypt the radio signal without any a priori common secret between the two nodes, was previously proposed by the authors [1]-[3]. The information is modulated, at physical layer, by the thermal noise experienced by the link between two terminals. A loop scheme is designed for unique recovering of mutual information. This contribution improves the previous works by exploring the real robustness of the proposed technique against the presence of DOS warriors and impairment of the radio channel, considering also implementation details, such as the bit integration time. Both the case of passive and active attacks have also been implemented and simulated by using the Matlab Simulink.
The issues of privacy and security in wireless communication networks have taken on an increasingly important role as these networks continue to be deployed worldwide. Traditionally, security is viewed as an independent feature addressed above the physical layer and all widely used cryptographic protocols are designed and implemented assuming that the physical layer simply provides an error-free link. However, with the emergence of ad-hoc and decentralized networks, higher-layer techniques, such as encryption, are becoming complex and hard to be implemented, in particular in handy devices. Recently attention was moved to study the fundamental ability of the physical layer to provide secure wireless communications. In this contribution, we analyze, from an information-theoretic perspective, the performance of the Noise-Loop (NL) modulation, a physical-layer security technique previously presented in [1]. The capacity as well as the secrecy capacity of the NL modulation are derived and compared to a generic Gaussian channel. The results show that the proposed NL technique is able to produce a full-secrecy rate radio communication link.
Next generation 5G wireless networks pose several important security challenges. One fundamental challenge is key management between the two communicating parties. The goal is to establish a common secret key through an unsecured wireless medium. In this paper, we introduce a new physical layer paradigm for secure key exchange between the legitimate communication parties in the presence of a passive eavesdropper. The proposed method ensures secrecy via pre-equalization and guarantees reliable communications by the use of Low Density Parity Check (LDPC) codes. One of the main findings of this paper is to demonstrate through simulations that the diversity order of the eavesdropper will be zero unless the main and eavesdropping channels are almost correlated, while the probability of key mismatch between the legitimate transmitter and receiver will be low. Simulation results demonstrate that the proposed approach achieves very low secret key mismatch between the legitimate users, while ensuring very high error probability at the eavesdropper.
The ubiquity of wireless connectivity between an ever-increasing number of devices has confirmed dire past predictions of widespread eavesdropping (among other security concerns) in wireless networks, further promoting the need for secure communications. Of particular interest are physical layer techniques which exploit error-correction coding intrinsic to digital transceivers and which offer two clear advantages: (i) no need for key distribution; and (ii) secrecy that is not conditioned on a computationally limited adversary. Present techniques, however, assume some knowledge of the channel connecting the transmitter to the eavesdropper; if the eavesdropper is truly passive, this critical parameter is unavailable. We therefore examine secure communication schemes that do not assume knowledge of the eavesdropper's channel, yet remain keyless in their operation. Two schemes are offered, with behavior intermediate between cryptographic and information-theoretic solutions.
This paper introduces a novel physical layer secure communication technology based on wireless channel direct encryption to enhance the encryption strength of the information source. Unlike traditional methods of key generation based on the reciprocity of the wireless channel, which typically involve quantizing the wireless channel and then negotiating keys, resulting in two completely identical bit strings generated as encryption keys for upper-level cryptographic algorithms between legitimate communication parties, this paper's approach quantizes the quantized bits of the wireless channel characteristics of both legitimate parties and directly encrypts the information source bits by using a designed lightweight encryption/decryption algorithm. Compared to traditional approaches, this paper's method avoids the key consultation process for physical layer key distribution, expanding the scenarios for the use of physical layer keys. Moreover, it can work independently at the same time with the upper layer cryptography to enhance the encryption strength. Through experimental verification, it has been confirmed that, in cases where the channel error rate during information transmission is less than 5*10^-2, this model can achieve an average reception accuracy of 99.6% for legitimate communicators while ensuring that eavesdroppers cannot decrypt. This approach can also compatible with upper-layer security encryption/decryption algorithms at each layer of the OSI, e.g., data link layer and network layer, offering extensive application prospects.
Security is one of the key requirements of wireless communication systems. By exploiting the broadcast nature of wireless medium, a malicious user might attempt to mislead the legitimate nodes, intercept the communication and overhear the private information. In order to combat against such malicious attacks, various encryption using security techniques have been proposed in the literature. Recently, physical layer (PHY) security has emerged as an additional countermeasure to the encryption based approaches and become very popular. Unlike cryptography, PHY security techniques target to protect the signal itself rather than encrypting the information bits. However, most of these techniques are designed based on specific channel conditions. Since channel has a random nature and cannot be controlled by users, such a design approach may remain unreliable for many practical scenarios where the desired channel state does not exist. Therefore, in this study, we highlight the importance of the channel independent PHY security techniques. In order to draft the ongoing efforts and provide the open issues in this direction, three different concepts are discussed along with the reviews of sample studies.