Eavesdropping Model Research Articles

Secrecy analysis of collaborative NOMA networks with IQI

This paper studies the secrecy performance of collaborative non-orthogonal multiple access (NOMA) systems over κ–μ shadowed distribution with in-phase and quadrature-phase imbalance (IQI). The analytical expressions for outage probability (OP), intercept probability (IP), secure outage probability (SOP), and strictly positive secrecy capacity (SPSC) are derived relying on the NOMA eavesdropping model. Moreover, the Monte Carlo simulation perfectly coincides with the theoretical derivation, which confirms the accuracy of academic results. The numerical analysis indicates that IQI reduces reliability but enhances the secrecy of relaying NOMA networks. Additionally, the increase of kN or the decrease of μS can weaken the antijamming capability, whereas reducing mS or mE will strengthen the confidentiality. Furthermore, to realize real-time secrecy analysis, we investigate the anti-interference ability of the relaying system by the Elman neural network. Compared to other algorithms, the prediction accuracy is improved by 56.4% on average, and the runtime is decreased.

An efficient eavesdropping model for detection of advanced persistent threat (APT) in high volume network traffic

An efficient eavesdropping model for detection of advanced persistent threat (APT) in high volume network traffic

Waveform-Defined Security: A Low-Cost Framework for Secure Communications

Communication security could be enhanced at physical layer but at the cost of complex algorithms and redundant hardware, which would render traditional physical layer security (PLS) techniques unsuitable for use with resource-constrained communication systems. This work investigates a waveform-defined security (WDS) framework, which differs fundamentally from traditional PLS techniques used in today's systems. The framework is not dependent on channel conditions such as signal power advantage and channel state information (CSI). Therefore, the framework is more reliable than channel dependent beamforming and artificial noise (AN) techniques. In addition, the framework is more than just increasing the cost of eavesdropping. By intentionally tuning waveform patterns to weaken signal feature diversity and enhance feature similarity, eavesdroppers will not be able to identify correctly signal formats. The wrong classification of signal formats would result in subsequent detection errors even when an eavesdropper uses brute-force detection techniques. To get a robust WDS framework, three impact factors, namely training data feature, oversampling factor and bandwidth compression factor (BCF) offset, are investigated. An optimal WDS waveform pattern is obtained at the end after a joint study of the three factors. To ensure a valid eavesdropping model, artificial intelligence (AI) dependent signal classifiers are designed followed by optimal performance achievable signal detectors. To show the compatibility in available communication systems, the WDS framework is successfully integrated in IEEE 802.11a with nearly no adding computational complexity. Finally, a low-cost software-defined radio (SDR) experiment is designed to verify the feasibility of the WDS framework in resource-constrained communications.

Line-of-sight quantum key distribution with differential phase shift keying

Free-space optical (FSO) links offer a practical approach to realize quantum key distribution (QKD) in a global scale. However, when one wants to further extend the distance from the geostationary orbit to the ground, currently known QKD schemes cannot realize practical key rates mainly due to the diffraction losses of a laser beam. If the facts that the FSO links are highly directional and must be used in the line-of-sight (LoS) condition are taken into account, one may impose some physical restrictions on an eavesdropping model to explore longer-distance QKD. In this paper, we propose a novel FSO secret key agreement scheme, line-of-sight QKD (LoS-QKD), based on a quantum wiretap channel. In our model, an eavesdropper can tap only a limited fraction of the FSO signal beam but perform any physically allowable operations on the tapped signals. Fading effects which are significant in the FSO links are fully taken into account. We provide a security proof for the differential phase shift (DPS) keying scheme in terms of the metric which meets the composability. We investigate numerically the performances of LoS-QKD with DPS keying, including finite-length analysis, showing that our proposed scheme can realize high-speed and long-distance secret key agreement with information-theoretic security.

A new framework for deniable secure key exchange

A deniable secure key exchange protocol allows two parties to agree on a common secret while achieving two seemingly contradictory functionalities: authentication and deniability. The former requires each party to confirm the identity of the other while the latter requires any attacker (e.g., participant or eavesdropper) be unable to prove to a third party an honest party's participation. Designing an efficient secure key exchange with deniability is a challenging problem. In this paper, we first formalize the deniability model by requiring information theoretic deniability with an eavesdropping attack. The information theoretic deniability has the advantage that it can hold forever without any computational assumption. An eavesdropping attack (Di Raimondo et al., CCS'06) allows an attacker to apply eavesdropped transcripts into an active attack session. This gives an attacker more power to make the victim undeniable as he does not know the randomness of the transcript. We then propose an efficient, provably deniable secure framework of key exchange. Our deniability holds non-adaptively in the eavesdropping model. However, if we consider a model without an eavesdropping attack (which is practical in many scenarios), then our framework is proven adaptively deniable. This is important since no previous key exchange protocols can satisfy our adaptive and information theoretical deniability. We give a concrete realization for our framework that is more efficient than SKEME (Krawczyk, NDSS'96).

A Friendly Jamming Handover Scheme for a Conscious Mobile Eavesdropper in IoT systems

Physical layer security (PLS) in Internet-of-Things (IoT) has attracted great attention in recent years. As an important and intrinsic property in an IoT system, node mobility is not fully investigated when designing a PLS scheme. Existing PLS works with mobility are designed with typical random mobile models, which cannot represent a real scenario. Considering this challenge, we propose a friendly jamming handover scheme to protect the downlink transmission from a controller to an actuator, with the help of multiple cooperative jammers to fight against a mobile conscious eavesdropper. In particular, we first introduce a conscious eavesdropping model (CEM) to characterize a real mobile wiretapping scenario. Second, we present a handover scheme to enhance security in a mobile scenario and then define handover efficiency to discuss the handover performance. Finally, numerical results are provided to verify the effectiveness of the proposed handover scheme, which demonstrates that our scheme can efficiently fight against a conscious mobile eavesdropper.

Geometrical Optics Restricted Eavesdropping Analysis of Satellite-to-Satellite Secret Key Distillation.

Traditionally, the study of quantum key distribution (QKD) assumes an omnipotent eavesdropper that is only limited by the laws of physics. However, this is not the case for specific application scenarios such as the QKD over a free-space link. In this invited paper, we introduce the geometrical optics restricted eavesdropping model for secret key distillation security analysis and apply to a few scenarios common in satellite-to-satellite applications.

Secrecy Enhancing of SSK Systems for IoT Applications in Smart Cities

The secure exchange of messages between different communication devices is a major issue of Internet-of-Things (IoT) applications in future smart cities. Current security mechanisms focus on multiple antennas technology, such as spatial modulation (SM), but in space shift keying (SSK), there is still a space to explore. In this article, we propose a secrecy-enhancing SSK scheme for IoT applications by applying security technologies in the physical layer wherein the number of transmit antennas is arbitrary rather than the value of power of two. In this scheme, the security performance of the communication system is improved by using two technologies, namely, artificial noise (AN) and antenna selection. We assume that the application scenario of the SSK system is under the classic eavesdropping model. First, we design ANs according to the channel state information (CSI) to interrupt the eavesdropper and benefit the legitimate receiver via the appropriate cancellation technology. Second, the antenna selection method is designed based on the signal to leakage noise ratio (SLNR) to further boost the secrecy performance by expanding the mutual information difference between the main channel and the eavesdropping channel. Results from our simulations indicate that by the use of the proposed scheme, significant secrecy enhancing can be achieved in terms of bit error ratio (BER) and secrecy rate (SR) when compared with existing schemes. This achieved secrecy enhancing can benefit the suitable IoT communication applications in the smart city environment to avoid the leakage of data transmission.

Secret-Key Distillation across a Quantum Wiretap Channel under Restricted Eavesdropping

The theory of quantum cryptography aims to guarantee unconditional information-theoretic security against an omnipotent eavesdropper. In many practical scenarios, however, the assumption of an all-powerful adversary is excessive and can be relaxed considerably. In this paper we study secret key distillation across a lossy and noisy quantum wiretap channel between Alice and Bob, with a separately parameterized realistically lossy quantum channel to the eavesdropper Eve. We show that under such restricted eavesdropping, the key rates achievable can exceed the secret key distillation capacity against an unrestricted eavesdropper in the quantum wiretap channel. Further, we show upper bounds on the key rates based on the relative entropy of entanglement. This simple restricted eavesdropping model is widely applicable, e.g., to free-space quantum optical communication, where realistic collection of light by Eve is limited by the finite size of her optical aperture. Future work will include calculating bounds on the amount of light Eve can collect under various realistic scenarios.

On Secure Exact-Repair Regenerating Codes With a Single Pareto Optimal Point

The problem of exact-repair regenerating codes against eavesdropping attack is studied. The eavesdropping model we consider is that the eavesdropper has the capability to observe the data involved in the repair of a subset of $\ell $ nodes. An $(n,k,d,\ell )$ secure exact-repair regenerating code is an $(n,k,d)$ exact-repair regenerating code that is secure under this eavesdropping model. It has been shown that for some parameters $(n,k,d,\ell )$ , the associated optimal storage-bandwidth tradeoff curve, which has one corner point, can be determined. The focus of this paper is on characterizing such parameters. We establish a lower bound $\hat {\ell }$ on the number of wiretap nodes, and show that this bound is tight for the case $k = d = n-1$ .

Chain Inequality Violation with Quantum Weak Measurement Technology**Supported by National Natural Science Foundation of China under Grant Nos. 61675235, 11304397, and National Key Research and Development Program of China under Grant No. 2016YFA0302600

Bell inequality is an important resource in the quantum information theory, which can be applied to guarantee security of the device independent quantum information protocols. By utilizing the quantum weak measurement technology, we propose the Chain inequality violation with three parties, and the analysis result demonstrates that double Chain inequality violation can be observed in the case of Alice and Bob have two different measurement bases. Since the weak measurement model can be assumed to be an eavesdropping model, our analysis model may be applied to analyze security of the device independent quantum information protocols.

Performance analysis of FSO/CDMA system based on binary symmetric wiretap channel

Transmission reliability, security, and efficiency are of great importance to free space optical (FSO) communication. For the first time, the authors obtain optimal parameters for the FSO/code division multiple access (CDMA) system taking into account the transmission reliability, security, and efficiency simultaneously. By establishing the eavesdropping model of the FSO/CDMA binary symmetric wiretap channel (BSWC), the performance of physical-layer security and reliability are evaluated simultaneously. Intercept probability is derived for FSO/CDMA BSWC, considering atmospheric attenuation, atmospheric turbulence, shot noise, thermal noise, background noise and multiple access interference (MAI). The effects of transmission distance, code length, transmission power and a number of interfering users on the physical-layer security and reliability are discussed. It is shown that, in order to meet the legitimate user's reliability and security simultaneously, the number of interfering users and code length must be in a certain interval. Furthermore, the maximum spectral efficiency can be obtained by selecting the transmission rate. These results open a new way of researching the FSO/CDMA system, where security, reliability, and spectral efficiency should be taken into account simultaneously.

A two-stage amplifier of laser eavesdropping model based on waveguide fiber taper

Abstract In order to improve ability of amplification about optical arrival angle in laser eavesdropping system, and enhance receiving field of view (FOV) of laser eavesdropping system, this paper presents a new multi-stage amplifier laser eavesdropping model based on waveguide fiber taper. First of all, taking about four-quadrant (4QD) laser eavesdropping model as an example, from the theoretical view, analyses factors that, currently, laser eavesdropping system face many restrictive factors during practical applications. Besides, from the receiving FOV and ability of amplification about arrival angle of incoming optical axis angles, systematically analyses advantages of multi-stage amplifier model. What's more, through constructing laser eavesdropping test platform, we demonstrate Signal to Noise Ratio (SNR) of two stage amplification model is eventually promoted to 6–10 dB compared with one amplifying model, especially in low and high audio level, the advantages is more obvious.

Secure Communications Over Wireless Broadcast Networks: Stability and Utility Maximization

A wireless broadcast network model with secrecy constraints is investigated, in which a source node broadcasts K confidential message flows to K user nodes, with each message intended to be decoded accurately by one user and to be kept secret from all other users (who are thus considered to be eavesdroppers with regard to all other messages but their own). The source maintains a queue for each message flow if it is not served immediately. The channel from the source to the K users is modeled as a fading broadcast channel, and the channel state information is assumed to be known to the source and the corresponding receivers. Two eavesdropping models are considered. For a collaborative eavesdropping model, in which the eavesdroppers exchange their outputs, the secrecy capacity region is obtained, within which each rate vector is achieved by using a time-division scheme and a source power control policy over channel states. A throughput optimal queue-length-based rate scheduling algorithm is further derived that stabilizes all arrival rate vectors contained in the secrecy capacity region. Moreover, the network utility function is maximized via joint design of rate control, rate scheduling, power control, and secure coding. More precisely, a source controls the message arrival rate according to its message queue, the rate scheduling selects a transmission rate based the queue length vector, and the rate vector is achieved by power control and secure coding. These components work jointly to solve the network utility maximization problem. For a noncollaborative eavesdropping model, in which eavesdroppers do not exchange their outputs, an achievable secrecy rate region is derived based on a time-division scheme, and the queue-length-based rate scheduling algorithm and the corresponding power control policy are obtained that stabilize all arrival rate vectors in this region. The network utility maximizing rate control vector is also obtained.

Vulnerability of MRD-Code-based Universal Secure Network Coding against Stronger Eavesdroppers

Silva et al. proposed a universal secure network coding scheme based on MRD codes, which can be applied to any underlying network code. This paper considers a stronger eavesdropping model where the eavesdroppers possess the ability to re-select the tapping links during the transmission. We give a proof for the impossibility of attaining universal security against such adversaries using Silva et al.'s code for all choices of code parameters, even with restricted number of tapped links. We also consider the cases with restricted tapping duration and derive some conditions for this code to be secure.