Biblio

Reconfigurable Intelligent Surface (RIS) is a new paradigm that enables the reconfiguration of the wireless environment. Based on this feature, RIS can be employed to facilitate Physical-layer Key Generation (PKG). However, this technique could also be exploited by the attacker to destroy the key generation process via manipulating the channel features at the legitimate user side. Specifically, this paper proposes a new RIS-assisted Manipulating attack (RISM) that reduces the wireless channel reciprocity by rapidly changing the RIS reflection coefficient in the uplink and downlink channel probing step in orthogonal frequency division multiplexing (OFDM) systems. The vulnerability of traditional key generation technology based on channel frequency response (CFR) under this attack is analyzed. Then, we propose a slewing rate detection method based on path separation. The attacked path is removed from the time domain and a flexible quantization method is employed to maximize the Key Generation Rate (KGR). The simulation results show that under RISM attack, when the ratio of the attack path variance to the total path variance is 0.17, the Bit Disagreement Rate (BDR) of the CFR-based method is greater than 0.25, and the KGR is close to zero. In addition, the proposed detection method can successfully detect the attacked path for SNR above 0 dB in the case of 16 rounds of probing and the KGR is 35 bits/channel use at 23.04MHz bandwidth.

Security preservation is considered as one of the major concerns in this digital world, mainly for performing any online transactions. As the time progress, it witnesses an enormous amount of security threats and stealing different kind of digital information over the online network. In this regard, lots of cryptographic algorithms based on secret key generation techniques have been implemented to boost up the security aspect of network systems that preserve the confidentiality of digital information. Despite this, intelligent intruders are still able to crack the key generation technique, thus stealing the data. In this research article, we propose an innovative approach for generating a pseudo-pseudo-random key sequence that serves as a base for the encryption/decryption process. The key generation process is carried out by extracting the essential features from a facial image and based on the extracted features; a pseudo-random key sequence that acts as a primary entity for the efficient encryption/decryption process is generated. Experimental findings related to the pseudo-random key is validated through chi-square, runs up-down and performs a period of subsequence test. Outcomes of these have subsequently passed in achieving an ideal key.

Internet of Things (IoT) enable information transmission and sharing among massive IoT devices. However, the key establishment and management in IoT become more challenging due to the low latency requirements and resource constrained IoT devices. In this work, we propose a practical physical layer based secret key sharing scheme for MIMO (multiple-input-multiple-output) IoT devices to reduce the communication delay caused by key establishment of MIMO IoT devices. This is because the proposed scheme attachs secret key sharing with communication simultaneously. It is achieved by the proposed MIMO self-injection AN (SAN) tranmsission, which is designed to deliberately maximum the receive SNR (signal to noise ratio) at different antenna of the legitimate IoT device, based on the value of secret key sharing to him. The simulation results verified the validity and security of the proposed scheme.

The open and broadcast nature of wireless channels makes eavesdropping possible, leading to the inherent problem of information leakage. Inherent problems should be solved by endogenous security functions. Accordingly, wireless security problems should be resolved by channel-based endogenous security mechanisms. Firstly, this paper analyzes the endogenous security principle of the physical-layer-secret-key method. Afterward, we propose a novel conjecture that in a fast-fading environment, there must exist wireless systems where the endogenous secret key rate can match the user data rate. Moreover, the conjecture is well founded by the instantiation validation in a wireless system with BPSK inputs from the perspectives of both theoretical analysis and simulation experiments. These results indicate that it is possible to accomplish the one-time pad via endogenous secret keys in wireless communication.

This paper considers the transmission of confidential data over wireless channels. Based on an information-theoretic formulation of the problem, in which two legitimates partners communicate over a quasi-static fading channel and an eavesdropper observes their transmissions through a second independent quasi-static fading channel, the important role of fading is characterized in terms of average secure communication rates and outage probability. Based on the insights from this analysis, a practical secure communication protocol is developed, which uses a four-step procedure to ensure wireless information-theoretic security: (i) common randomness via opportunistic transmission, (ii) message reconciliation, (iii) common key generation via privacy amplification, and (iv) message protection with a secret key. A reconciliation procedure based on multilevel coding and optimized low-density parity-check (LDPC) codes is introduced, which allows to achieve communication rates close to the fundamental security limits in several relevant instances. Finally, a set of metrics for assessing average secure key generation rates is established, and it is shown that the protocol is effective in secure key renewal-even in the presence of imperfect channel state information.

Secret key generation from wireless channel is an emerging technique of physical layer security. At present, most of the secret key generation schemes use information reconciliation to obtain symmetric keys. This paper introduces a non-interactive information reconciliation scheme based on channel coding and stream encryption, and considering the error correction capability, we design a concatenated code of BCH and RS codes as channel coding. The performance of concatenated error correction code has been analyzed in this scheme. Then, we compare the concatenated code with first-level error correction code in different test environments. Extensive numerical simulations and experiments demonstrate that the decoding performance of this second-level concatenated code is better than the first-level error correction code, and it can also effectively eliminate third-party eavesdropping.

This paper presents the recent progress in studying the algorithmic computability of capacity expressions of secure communication systems. Several communication scenarios are discussed and reviewed including the classical wiretap channel, the wiretap channel with an active jammer, and the problem of secret key generation.

The requirements regarding network management defined by the continuously rising amount of interconnected devices in the industrial landscape turns it into an increasingly complex task. Associated by the fusion of technologies up to Cyber-Physical Production Systems (CPPS) and the Industrial Internet of Things (IIoT) with its multitude of communicating sensors and actuators new demands arise. In particular, the driving forces of this development, mobility and flexibility, are affecting today's networks. However, it is precisely these wireless solutions, as enabler for this advancement, that create new attack vectors and cyber-security threats. Furthermore, many cryptographic procedures, intended to secure the networks, require additional overhead, which is limiting the transmission bandwidth and speed as well. For this reason, new and efficient solutions must be developed and applied, in order to secure the existing, as well as the future, industrial communication networks. This work proposes a conceptual approach, consisting of a combination of Software-Defined Networking (SDN) and Physical Layer Security (PhySec) to satisfy the network security requirements. Use cases are explained that demonstrate the appropriateness of the approach and it is shown that this is a easy to use and resource efficient, but nevertheless sound and secure approach.

Key derivation from the physical layer features of the communication channels is a promising approach which can help the key management and security enhancement in communication networks. In this paper, we consider a key generation technique that quantizes the received signal phase to obtain the secret keys. We then study the effect of a jamming attack on this system. The jammer is an active attacker that tries to make a disturbance in the key derivation procedure and changes the phase of the received signal by transmitting an adversary signal. We evaluate the effect of jamming on the security performance of the system and show the ways to improve this performance. Our numerical results show that more phase quantization regions limit the probability of successful attacks.

In this paper an analog cellular neural network is proposed with application in physical unclonable function design. Dynamical behavior of the circuit and its high sensitivity to the process variation can be exploited in a challenge-response security system. The proposed circuit can be used as unclonable core module in the secure systems for applications such as device identification/authentication and secret key generation. The proposed circuit is designed and simulated in 45-nm bulk CMOS technology. Monte Carlo simulation for this circuit, results in unpolarized Gaussian-shaped distribution for Hamming Distance between 4005 100-bit PUF instances.

Wireless channel reciprocity can be successfully exploited as a common source of randomness for the generation of a secret key by two legitimate users willing to achieve confidential communications over a public channel. This paper presents an analytical framework to investigate the theoretical limits of secret-key generation when wireless multi-dimensional Gaussian channels are used as source of randomness. The intrinsic secrecy content of wide-sense stationary wireless channels in frequency, time and spatial domains is derived through asymptotic analysis as the number of observations in a given domain tends to infinity. Some significant case studies are presented where single and multiple antenna eavesdroppers are considered. In the numerical results, the role of signal-to-noise ratio, spatial correlation, frequency and time selectivity is investigated.