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Artificial noise (AN)-aided techniques have been considered to be promising and practical candidates for enhancing physical layer security. However, there has been a lack of analysis regarding the AN effect on the eavesdropper (EV) from the perspective of the signal-to-interference plus noise ratio (SINR) regarding the existence of the EV's channel state information (CSI) at the legitimate transmitter. In this paper, we analyze the performance of AN-aided secure transmission from the SINR perspective when a legitimate transmitter has and does not have the EV's CSI. Based on the analyzed EV's SINRs for the above two cases, the secrecy gap, which is the difference between the two secrecy capacities, is defined and analyzed. Based on the derived secrecy gap, we have analyzed the asymptotic performances of the secrecy capacity and gap when the number of antennas of the legitimate transmitter and the number of antennas of the EV have large values. Through asymptotic analysis, it is demonstrated that the AN-aided secure transmission under the practical environment (i.e., the case that the EV's CSI is not available at the legitimate transmitter) can nearly achieve an ideal performance (i.e., the performance when the EV's CSI is available at the legitimate transmitter) in a massive antenna system. [ABSTRACT FROM AUTHOR]

This paper introduces a class of symmetric ciphering systems with a finite secret key, which provides ideal secrecy, autonomy in key generation and distribution, and robustness against the probabilistic structure of messages (the Ideally Secret Autonomous Robust (ISAR) system). The ISAR system is based on wiretap polar codes constructed over an artificial wiretap channel with a maximum secrecy capacity of 0.5. The system autonomously maintains a minimum level of key equivocation by continuously refreshing secret keys without additional key generation and distribution infrastructure. Moreover, it can transform any stream ciphering system with a finite secret key of known length into an ISAR system without knowing and/or changing its algorithm. Therefore, this class of system strongly supports privacy, a critical requirement for contemporary security systems. The ISAR system's reliance on wiretap polar coding for strong secrecy ensures resistance to passive known plaintext attacks. Furthermore, resistance to passive attacks on generated refreshing keys follows directly from ideal secrecy and autonomy. The results presented offer an efficient methodology for synthesizing this class of systems with predetermined security margins and a complexity of the order of n log ⁡ n , where n is the block length of the applied polar code. [ABSTRACT FROM AUTHOR]

Quantum secure direct communication (QSDC) is a quantum communication paradigm that transmits confidential messages directly using quantum states. Measurement-device-independent (MDI) QSDC protocols can eliminate the security loopholes associated with measurement devices. To enhance the practicality and performance of MDI-QSDC protocols, we propose a one-photon-interference MDI QSDC (OPI-QSDC) protocol which transcends the need for quantum memory, ideal single-photon sources, or entangled light sources. The security of our OPI-QSDC protocol has also been analyzed using quantum wiretap channel theory. Furthermore, our protocol could double the distance of usual prepare-and-measure protocols, since quantum states sending from adjacent nodes are connected with single-photon interference, which demonstrates its potential to extend the communication distance for point-to-point QSDC. [ABSTRACT FROM AUTHOR]

Police collusion with drug market organizations is widespread around the world, but the nature of this collaboration remains poorly understood. This article draws on a unique data source to dissect the inner workings of police collusion: transcripts of wiretapped conversations, embedded in thousands of pages of court cases in which state agents have been prosecuted for collaborating with drug market groups. We catalogue and analyze the wide range of social interactions that constitute police collaboration with drug market groups and show that those interactions are often embedded in trust networks constituted by residential, professional, friendship, and kinship ties. Our findings signal the importance of reciprocal social ties surrounding police corruption and cast light on what we refer to as the clandestine hands of the state. [ABSTRACT FROM AUTHOR]

In this paper, we study the Greek wiretappings scandal, which was revealed in 2022 and attracted significant attention from the press and citizens. Specifically, we propose a methodology for collecting data and analyzing patterns of online public discussions on Twitter. We apply our methodology to the Greek wiretappings use case and present findings related to the evolution of the discussion over time, its polarization, and the role of the Media. The methodology can be of wider use and replicated to other topics. Finally, we publicly provide an open dataset and online resources with the results. [ABSTRACT FROM AUTHOR]

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, we consider the challenge of ensuring secure communication in block-fading wiretap channels using encoding techniques. We investigate the coding for block-fading wiretap channels using stacked lattice codes constructed over completely real number fields, which is a well-established technique. In this paper, we consider degree-four complex multiplication field 풦 = ℚ(ς8) over ℚ. We employ binary codes to generate a lattice over ℚ(ς8), which is subsequently used to form an integral lattice. The resulting integral lattice can be effectively applied to enhance the security of communication within block-fading wiretap channels. [ABSTRACT FROM AUTHOR]

Copyright of Security: Theory & Practice / Bezpieczeństwo.Teoria i Praktyka is the property of Andrzej Frycz Modrzewski Krakow University, AFM Publishing Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This graphic shows the structure of our network. In the preprocessing section, we used the Beer-Lambert law to convert the optical signals into hemodynamic HbR and HbO. We used an end-to-end structure without much preprocessing of the raw fNIRS signal. We input the signal with the number of channels C = 24 and the number of samples T = 351. the original MI and MA signals are first passed through a convolution block. The convolution block consists of a 2D time convolution, a depth convolution, and a separable convolution, each followed by a Batch Normalization layer, an ELU activation function, an average pooling layer, and a dropout layer. Afterwards, spatio-temporal feature extraction is performed by spatial attention and temporal convolutional networks, capable of reducing overfitting. Finally, the fNIRS signal is classified as MI or MA. The results show that the method using only 3.23 K training parameters has an accuracy of 85.63% (HbO) and 86.21% (HbR) in the MI task and 96.84% (HbO) and 94.83% (HbR) in the MA task. [Display omitted] • fNIRS decoding performance improvement. • Using Convolutional Neural Networks for fNIRS Classification. • Spatial attention mechanisms can capture remote contextual information. • Temporal convolutional network outperforms most RNN in time-series tasks. Brain Computer Interface (BCI) is a highly promising human–computer interaction method that can utilize brain signals to control external devices. BCI based on functional near-infrared spectroscopy (fNIRS) is considered a relatively new and promising paradigm. fNIRS is a technique of measuring functional changes in cerebral hemodynamics. It detects changes in the hemodynamic activity of the cerebral cortex by measuring oxyhemoglobin and deoxyhemoglobin (HbR) concentrations and inversely predicts the neural activity of the brain. At the present time, Deep learning (DL) methods have not been widely used in fNIRS decoding, and there are fewer studies considering both spatial and temporal dimensions for fNIRS classification. To solve these problems, we proposed an end-to-end hybrid neural network for feature extraction of fNIRS. The method utilizes a spatial–temporal convolutional layer for automatic extraction of temporally valid information and uses a spatial attention mechanism to extract spatially localized information. A temporal convolutional network (TCN) is used to further utilize the temporal information of fNIRS before the fully connected layer. We validated our approach on a publicly available dataset including 29 subjects, including left-hand and right-hand motor imagery (MI), mental arithmetic (MA), and a baseline task. The results show that the method has few training parameters and high accuracy, providing a meaningful reference for BCI development. [ABSTRACT FROM AUTHOR]

A wiretap coding scheme (Wyner in Bell Syst Tech J 54(8):1355–1387, 1975) enables Alice to reliably communicate a message m to an honest Bob by sending an encoding c over a noisy channel ChB , while at the same time hiding m from Eve who receives c over another noisy channel ChE . Wiretap coding is clearly impossible when ChB is a degraded version of ChE , in the sense that the output of ChB can be simulated using only the output of ChE . A classic work of Csiszár and Korner (IEEE Trans Inf Theory 24(3):339–348, 1978) shows that the converse does not hold. This follows from their full characterization of the channel pairs (ChB , ChE) that enable information-theoretic wiretap coding. In this work, we show that in fact the converse does hold when considering computational security; that is, wiretap coding against a computationally bounded Eve is possible if and only if ChB is not a degraded version of ChE . Our construction assumes the existence of virtual black-box obfuscation of specific classes of "evasive" functions that generalize fuzzy point functions and can be heuristically instantiated using indistinguishability obfuscation. Finally, our solution has the appealing feature of being universal in the sense that Alice's algorithm depends only on ChB and not on ChE . [ABSTRACT FROM AUTHOR]

This paper examines the multi-layered translational process of intercepted conversations which appear as evidence in court files in the form of translated wiretap records. The translational challenge here is to transfer the multimodal content of a spoken text in the source language into a written text in the target language. Based on audio data from 17 original intercepted communications and case file documents from a Swiss criminal investigation, the multimodality of the resulting hybrid translational action is explored. In this paper, the process of interlingual decontextualisation and recontextualisation of intercepted communication is examined from the bottom up. The analysis shows that there are different levels of contextualisation that must be considered to achieve a fuller picture of the meaning of a wiretapped conversation. [ABSTRACT FROM AUTHOR]

In this paper, we study a three-layer wiretap network including the source node in the top layer, N nodes in the middle layer and L sink nodes in the bottom layer. Each sink node recovers the message generated from the source node correctly via the middle layer nodes that it has access to. Furthermore, it is required that an eavesdropper eavesdropping a subset of the channels between the top layer and the middle layer learns absolutely nothing about the message. For each pair of decoding and eavesdropping patterns, we are interested in finding the capacity region consisting of (N + 1) -tuples, with the first element being the size of the message successfully transmitted and the remaining elements being the capacity of the N channels from the source node to the middle layer nodes. This problem can be seen as a generalization of the secret sharing problem. We show that when the number of middle layer nodes is no larger than four, the capacity region is fully characterized as a polyhedral cone. When such a number is 5, we find the capacity regions for 74,222 decoding and eavesdropping patterns. For the remaining 274 cases, linear capacity regions are found. The proving steps are: (1) Characterizing the Shannon region, an outer bound of the capacity region; (2) Characterizing the common information region, an outer bound of the linear capacity region; (3) Finding linear schemes that achieve the Shannon region or the common information region. [ABSTRACT FROM AUTHOR]

Due to atmospheric turbulence, the reliability and security of free space optical (FSO) communication will be affected seriously. In this paper, we propose a novel scheme of quasisynchronous spatial diversity free-space optical code division multiple access (FSO-CDMA) wiretap channel based on gamma-gamma distribution. Considering multiple access interference, shot noise, thermal noise and background noise, performances of bit error rate (BER) and physical-layer security are analyzed theoretically. The physical-layer security of quasisynchronous spatial diversity FSO-CDMA wiretap channel is evaluated by secrecy capacity and interception probability. Closed-form expression of interception probability is obtained. In order to compare the performances between conventional spatial diversity FSO-CDMA and the proposed scheme, Optisystem simulation is carried out. The results indicate that quasisynchronous spatial diversity FSO-CDMA scheme can improve the reliability and physical-layer security simultaneously. [ABSTRACT FROM AUTHOR]

In this paper, we want to investigate classical-quantum multiple access wiretap channels (CQ-MA-WTC) under one-shot setting. In this regard, we analyze the CQ-MA-WTC using a simultaneous position-based decoder for reliable decoding and using a newly introduced technique to decode securely. Also, for the sake of comparison, we analyze the CQ-MA-WTC using Sen's one-shot joint typicality lemma for reliable decoding. The simultaneous position-based decoder tends to a multiple hypothesis testing problem. Also, using convex splitting to analyze the privacy criteria in a simultaneous scenario becomes problematic. To overcome both problems, we first introduce a new channel that can be considered as a dual to the CQ-MA-WTC. This channel is called a point-to-point quantum wiretap channel with multiple messages (PP-QWTC). In the following, as a strategy to solve the problem, we also investigate and analyze quantum broadcast channels (QBC) in the one-shot regime. [ABSTRACT FROM AUTHOR]

Many physical-layer security works in the literature rely on purely theoretical work or simulated results to establish the value of physical-layer security in securing communications. We consider the secrecy capacity of a wireless Gaussian wiretap channel using channel sounding measurements to analyze the potential for secure communication in a real-world scenario. A multi-input, multi-output, multi-eavesdropper (MIMOME) system is deployed using orthogonal frequency division multiplexing (OFDM) over an 802.11n wireless network. Channel state information (CSI) measurements were taken in an indoor environment to analyze time-varying scenarios and spatial variations. It is shown that secrecy capacity is highly affected by environmental changes, such as foot traffic, network congestion, and propagation characteristics of the physical environment. We also present a numerical method for calculating MIMOME secrecy capacity in general and comment on the use of OFDM with regard to calculating secrecy capacity. [ABSTRACT FROM AUTHOR]

Secrecy capacity is usually employed as the performance metric of the physical layer security in fiber-optic wiretap channels. However, secrecy capacity can only qualitatively evaluate the physical layer security, and it cannot quantitatively evaluate the physical layer security of an imperfect security system. Furthermore, secrecy capacity cannot quantitatively evaluate the amount of information leakage to the eavesdropper. Based on the channel model of an optical CDMA network using wiretap code, the information leakage rate is analyzed to evaluate the physical layer security. The numerical results show that the information leakage rate can quantitatively evaluate the physical layer security of an optical CDMA wiretap channel, and it is related to transmission distance, eavesdropping position, confidential information rate and optical code. [ABSTRACT FROM AUTHOR]

The hidden transmission of information takes place via covert channels. Contrary to encryption, which just shields data from unauthorized eyes, covert channels work to conceal the communication's actual existence. The Internet is a perfect high-capacity platform for clandestine communication because of the sheer volume of data it contains and the wide variety of network protocols it supports. Because they may be used by criminals to conceal their communication activity, covert channels offer a severe security risk. In this study, we introduce a unique covert channel that operates within the Time To Live (TTL) field of the IP header. The sender modifies the TTLs of subsequent packets to convey hidden information to the receiver. This channel relies on "natural" TTL variation for its capacity and covertness since network nodes along the path likewise vary the TTL. We investigate this fluctuation over many traffic traces and suggest an encoding method. We also discuss the detection of real andfake messages send by the sender and it is detected by warden in covert channel. [ABSTRACT FROM AUTHOR]

The goal to be achieved in this paper is an analysis of efforts to prevent and eradicate criminal acts of corruption in the Attorney General's Office must have additional authority to carry out wiretapping because the Attorney's authority in wiretapping corruption in the Prosecutor's Law of the Republic of Indonesia has not yet been regulated. The problems that occur include the attorney's authority to tap acts of corruption regulated in another law, namely the Electronic Transaction Information Law. The method used is normative legal research. The result of the discussion is that the prosecutor's authority in wiretapping corruption in the future is to revise the Attorney General's Law of the Republic of Indonesia, which gives the prosecutor's authority in wiretapping corruption for the sake of the effectiveness and efficiency of the Attorney's performance, because the accuracy of wiretapping results can be accounted for, as well as optimizing the handling of corruption cases by the Attorney Great. How to cite item: Ali, Romli Said, Muhammad Sadi Is, and Belmento. “The Attorney's Authority in Conducting Wiretapping of The Corruption Crimes.” Jurnal Cakrawala Hukum. 14 no. 1 (2023): 54-62. DOI: 10.26905/idjch.v14i1.9079.