1,720,992 research outputs found
VLC Physical Layer Security through RIS-aided Jamming Receiver for 6G Wireless Networks
Full text linkVisible Light Communication (VLC) is one the most promising enabling
technology for future 6G networks to overcome Radio-Frequency (RF)-based
communication limitations thanks to a broader bandwidth, higher data rate, and
greater efficiency. However, from the security perspective, VLCs suffer from
all known wireless communication security threats (e.g., eavesdropping and
integrity attacks). For this reason, security researchers are proposing
innovative Physical Layer Security (PLS) solutions to protect such
communication. Among the different solutions, the novel Reflective Intelligent
Surface (RIS) technology coupled with VLCs has been successfully demonstrated
in recent work to improve the VLC communication capacity. However, to date, the
literature still lacks analysis and solutions to show the PLS capability of
RIS-based VLC communication. In this paper, we combine watermarking and jamming
primitives through the Watermark Blind Physical Layer Security (WBPLSec)
algorithm to secure VLC communication at the physical layer. Our solution
leverages RIS technology to improve the security properties of the
communication. By using an optimization framework, we can calculate RIS phases
to maximize the WBPLSec jamming interference schema over a predefined area in
the room. In particular, compared to a scenario without RIS, our solution
improves the performance in terms of secrecy capacity without any assumption
about the adversary's location. We validate through numerical evaluations the
positive impact of RIS-aided solution to increase the secrecy capacity of the
legitimate jamming receiver in a VLC indoor scenario. Our results show that the
introduction of RIS technology extends the area where secure communication
occurs and that by increasing the number of RIS elements the outage probability
decreases
Eavesdropping of RIS-integrated Terahertz HAPS-enabled satellite communication
No full textopenSatellite Communication (SatCom) systems are evolving rapidly to meet increasing demands for high-speed data transmission. In this context, the Terahertz (THz) frequency band has gained attention due to its untapped high bandwidth, but introduces new Physical Layer Security (PLS) challenges, especially in uplinks to Low Earth Orbit (LEO) satellites, where scattering due to atmospheric influence may enable interception outside the main beam. Integrating a Reconfigurable Intelligent Surface (RIS)-enabled High-Altitude Platform Station (HAPS) as a relay node offers a promising approach to mitigating these security risks.
In this work, we propose, to the best of our knowledge, the first deterministic 2D single-scattering model specifically tailored to evaluate Non-Line-Of-Sight (NLOS) eavesdropping risks in THz-band satellite uplinks. The model includes atmospheric attenuation, Free Space Path Loss (FSPL), and single-scattering effects to analytically compute the Signal-to-Noise Ratio (SNR) and Secrecy Capacity (SC) for both legitimate and eavesdropping links under varying weather conditions. Simulations reveal non-negligible insecure spatial areas around the communication beam where the SC drops to zero. However, using a RIS-enabled HAPS reduces this area by 48%. These findings reveal key physical-layer risks in THz communication while simultaneously showing the potential of RIS-assisted HAPS in securing THz-frequency Non-Terrestrial Network (NTN) uplinks against these risks.Satellite Communication (SatCom) systems are evolving rapidly to meet increasing demands for high-speed data transmission. In this context, the Terahertz (THz) frequency band has gained attention due to its untapped high bandwidth, but introduces new Physical Layer Security (PLS) challenges, especially in uplinks to Low Earth Orbit (LEO) satellites, where scattering due to atmospheric influence may enable interception outside the main beam. Integrating a Reconfigurable Intelligent Surface (RIS)-enabled High-Altitude Platform Station (HAPS) as a relay node offers a promising approach to mitigating these security risks.
In this work, we propose, to the best of our knowledge, the first deterministic 2D single-scattering model specifically tailored to evaluate Non-Line-Of-Sight (NLOS) eavesdropping risks in THz-band satellite uplinks. The model includes atmospheric attenuation, Free Space Path Loss (FSPL), and single-scattering effects to analytically compute the Signal-to-Noise Ratio (SNR) and Secrecy Capacity (SC) for both legitimate and eavesdropping links under varying weather conditions. Simulations reveal non-negligible insecure spatial areas around the communication beam where the SC drops to zero. However, using a RIS-enabled HAPS reduces this area by 48%. These findings reveal key physical-layer risks in THz communication while simultaneously showing the potential of RIS-assisted HAPS in securing THz-frequency Non-Terrestrial Network (NTN) uplinks against these risks
Inferring personal attributes with a millimeter wave radar
No full textreservedThis thesis employs a millimeter wave radar system for the analysis of gait patterns in various data subjects using point cloud data. This thesis aims to employ a deep learning model for extracting valuable insights from the point clouds and making inferences regarding the personal attributes of individuals, such as gender or height.This thesis employs a millimeter wave radar system for the analysis of gait patterns in various data subjects using point cloud data. This thesis aims to employ a deep learning model for extracting valuable insights from the point clouds and making inferences regarding the personal attributes of individuals, such as gender or height
A method for Internet of Things authentication relying on invisible physical differences in the DRAM
No full textopenA method that uses imperceptible differences in DRAM modules for authenticating IoT devices is proposedA method that uses imperceptible differences in DRAM modules for authenticating IoT devices is propose
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Teollisuuden langattomien tietoliikennejärjestelmien turvallisuuden arviointi
No full textAbstractThe worldwide success of wireless communications was originally fueled by the possibility to replace existing cables with wireless solutions. This phenomenon imposed the development of security engineering as a multidisciplinary field. Although wireless solutions can reduce installation costs and allow introducing new services, the end–users expect it to have the same level of security as they would normally have with wired solutions. Secure communications is an important part of the overall security of industrial wireless communications systems (IWCS).The aim of this thesis is to develop new security engineering methodologies for IWCS. The author develops countermeasures against confidentiality and integrity attacks and carries out a security analysis covering the protocol, electromagnetic and physical layer. In the first part of the thesis, Host Identity Protocol (HIP) is utilized to secure communication in an intra–vehicular network. Simulations and measurement campaigns are also conducted to evaluate the impact of the overhead on security in a tunnel, considering line–of–sight (LOS) and non–LOS (NLOS) scenarios.Electromagnetic analysis (EMA) is an important step in the development of safety–related systems. Today, the increasing usage of smaller integrated circuit also increases the susceptibility to electromagnetic (EM) interference. From near–field (NF) to far–field (FF) transformation, a method for the evaluation of the emissions leakage is investigated. The virtual EM (VEM) interface of the device–under–test (DUT) is studied, and it is described how an adversary can exploit it for denial of service (DoS) attacks. An effective jamming attack model is studied, and the theoretical calculations are validated with experiment–based results.Finally, focusing attention on physical layer security, two algorithms are developed. Active radio frequency fingerprinting (RFF) implements the exchange of a public key during the setup of secure communication. Afterwards, utilizing a jamming receiver in conjunction with the spread spectrum (SS) watermarking technique, the watermark–based blind physical layer security (WBPLSec) protocol is presented. The analysis and results indicate how the WBPLSec seems to be a valuable technique for deploying physical layer security by creating a secure region around the receiver.TiivistelmäLangattoman tietoliikenteen maailmanlaajuista suosiota kiihdytti alun perin mahdollisuus korvata tietoliikennejärjestelmissä käytetyt kaapelit langattomilla ratkaisuilla. Ilmiö lisäsi myös tarvetta kehittää alan turvatekniikkaa monialaisen tutkimuksen pohjalta. Vaikka langattomat ratkaisut merkitsevät pienempiä asennuskustannuksia ja tarjoavat mahdollisuuksia luoda uudenlaisia palveluja, järjestelmien loppukäyttäjät edellyttävät kuitenkin niiden turvallisuuden olevan vastaavalla tasolla kuin langallisissa verkoissa. Myös teollisuuden langattomien tietoliikennejärjestelmen turvallisuus riippuu pitkälti viestintäkanavien turvallisuudesta.Väitöksen tavoitteena on kehittää uusia menetelmiä, joilla teollisuuden langattomat tietoliikennejärjestelmät voitaisiin turvata. Väitöksessä kehitetään toimenpiteitä tietoliikennejärjestelmien luottamuksellisuuteen ja koskemattomuuteen kohdistuvia hyökkäyksiä vastaan ja toteutetaan turvallisuusarviointi, joka kattaa järjestelmän protokollakerroksen sekä sähkömagneettisen ja fyysisen kerroksen. Väitöksen ensimmäisessä osassa hyödynnetään HIP–protokollaa (Host Identity Protocol) liikennevälineen sisäisen tietoliikennejärjestelmän turvallisuuden varmistamisessa. Lisäksi siinä kuvataan simulaatiot ja mittaushankkeet, joiden tavoitteena on arvioida käytetyn protokollan turvallisuusvaikutuksia esteettömän (line–of–sight, LOS) ja esteellisen (non–line–of–sight, NLOS) näköyhteyden tapauksissa.Sähkömagneettinen analyysi on tärkeä vaihe turvajärjestelmien kehitysprosessissa. Järjestelmissä käytetään yhä enemmän pieniä integroituja piirejä, mikä voi myös altistaa ne sähkömagneettisille (electromagnetic, EM) häiriöille. Väitöksessä tutkitaan lähikenttä–kaukokenttä -muunnokseen perustuvan arviointimenetelmän avulla sähkömagneettisen vuotosäteilyn tasoa. Lisäksi perehdytään testattavan laitteen (device under test, DUT) virtuaaliseen EM–liitäntään ja kuvataan, miten vastaavaa liitäntää voidaan hyödyntää palvelunestohyökkäyksissä. Väitöksessä tutkitaan myös tehokasta häirintämallia ja validoidaan teoreettisten laskelmien tulokset kokeellisesti.Lopuksi väitöksessä keskitytään tietoliikennejärjestelmän fyysisen kerroksen turvallisuuteen ja kehitetään kaksi algoritmia. Aktiivisen radiotaajuisen tunnistusmenetelmän avulla voidaan vaihtaa julkisia avaimia turvallista tietoliikenneyhteyttä muodostettaessa. Lisäksi esitellään vesileimausmenetelmään perustuva fyysisen kerroksen salausmenetelmä, WBPLSec. WBPLSec luo vastaanottimen ympärille suoja–alueen, minkä ansiosta se vaikuttaa analyysin ja tutkimustulosten perusteella olevan tehokas menetelmä toteuttaa fyysisen kerroksen suojaus.Academic dissertation to be presented with the assent of the Doctoral Training Committee of Technology and Natural Sciences of the University of Oulu for public defence in the OP auditorium (L10), Linnanmaa, on 17 June 2016, at 12 noonAbstract
The worldwide success of wireless communications was originally fueled by the possibility to replace existing cables with wireless solutions. This phenomenon imposed the development of security engineering as a multidisciplinary field. Although wireless solutions can reduce installation costs and allow introducing new services, the end–users expect it to have the same level of security as they would normally have with wired solutions. Secure communications is an important part of the overall security of industrial wireless communications systems (IWCS).
The aim of this thesis is to develop new security engineering methodologies for IWCS. The author develops countermeasures against confidentiality and integrity attacks and carries out a security analysis covering the protocol, electromagnetic and physical layer. In the first part of the thesis, Host Identity Protocol (HIP) is utilized to secure communication in an intra–vehicular network. Simulations and measurement campaigns are also conducted to evaluate the impact of the overhead on security in a tunnel, considering line–of–sight (LOS) and non–LOS (NLOS) scenarios.
Electromagnetic analysis (EMA) is an important step in the development of safety–related systems. Today, the increasing usage of smaller integrated circuit also increases the susceptibility to electromagnetic (EM) interference. From near–field (NF) to far–field (FF) transformation, a method for the evaluation of the emissions leakage is investigated. The virtual EM (VEM) interface of the device–under–test (DUT) is studied, and it is described how an adversary can exploit it for denial of service (DoS) attacks. An effective jamming attack model is studied, and the theoretical calculations are validated with experiment–based results.
Finally, focusing attention on physical layer security, two algorithms are developed. Active radio frequency fingerprinting (RFF) implements the exchange of a public key during the setup of secure communication. Afterwards, utilizing a jamming receiver in conjunction with the spread spectrum (SS) watermarking technique, the watermark–based blind physical layer security (WBPLSec) protocol is presented. The analysis and results indicate how the WBPLSec seems to be a valuable technique for deploying physical layer security by creating a secure region around the receiver.Tiivistelmä
Langattoman tietoliikenteen maailmanlaajuista suosiota kiihdytti alun perin mahdollisuus korvata tietoliikennejärjestelmissä käytetyt kaapelit langattomilla ratkaisuilla. Ilmiö lisäsi myös tarvetta kehittää alan turvatekniikkaa monialaisen tutkimuksen pohjalta. Vaikka langattomat ratkaisut merkitsevät pienempiä asennuskustannuksia ja tarjoavat mahdollisuuksia luoda uudenlaisia palveluja, järjestelmien loppukäyttäjät edellyttävät kuitenkin niiden turvallisuuden olevan vastaavalla tasolla kuin langallisissa verkoissa. Myös teollisuuden langattomien tietoliikennejärjestelmen turvallisuus riippuu pitkälti viestintäkanavien turvallisuudesta.
Väitöksen tavoitteena on kehittää uusia menetelmiä, joilla teollisuuden langattomat tietoliikennejärjestelmät voitaisiin turvata. Väitöksessä kehitetään toimenpiteitä tietoliikennejärjestelmien luottamuksellisuuteen ja koskemattomuuteen kohdistuvia hyökkäyksiä vastaan ja toteutetaan turvallisuusarviointi, joka kattaa järjestelmän protokollakerroksen sekä sähkömagneettisen ja fyysisen kerroksen. Väitöksen ensimmäisessä osassa hyödynnetään HIP–protokollaa (Host Identity Protocol) liikennevälineen sisäisen tietoliikennejärjestelmän turvallisuuden varmistamisessa. Lisäksi siinä kuvataan simulaatiot ja mittaushankkeet, joiden tavoitteena on arvioida käytetyn protokollan turvallisuusvaikutuksia esteettömän (line–of–sight, LOS) ja esteellisen (non–line–of–sight, NLOS) näköyhteyden tapauksissa.
Sähkömagneettinen analyysi on tärkeä vaihe turvajärjestelmien kehitysprosessissa. Järjestelmissä käytetään yhä enemmän pieniä integroituja piirejä, mikä voi myös altistaa ne sähkömagneettisille (electromagnetic, EM) häiriöille. Väitöksessä tutkitaan lähikenttä–kaukokenttä -muunnokseen perustuvan arviointimenetelmän avulla sähkömagneettisen vuotosäteilyn tasoa. Lisäksi perehdytään testattavan laitteen (device under test, DUT) virtuaaliseen EM–liitäntään ja kuvataan, miten vastaavaa liitäntää voidaan hyödyntää palvelunestohyökkäyksissä. Väitöksessä tutkitaan myös tehokasta häirintämallia ja validoidaan teoreettisten laskelmien tulokset kokeellisesti.
Lopuksi väitöksessä keskitytään tietoliikennejärjestelmän fyysisen kerroksen turvallisuuteen ja kehitetään kaksi algoritmia. Aktiivisen radiotaajuisen tunnistusmenetelmän avulla voidaan vaihtaa julkisia avaimia turvallista tietoliikenneyhteyttä muodostettaessa. Lisäksi esitellään vesileimausmenetelmään perustuva fyysisen kerroksen salausmenetelmä, WBPLSec. WBPLSec luo vastaanottimen ympärille suoja–alueen, minkä ansiosta se vaikuttaa analyysin ja tutkimustulosten perusteella olevan tehokas menetelmä toteuttaa fyysisen kerroksen suojaus
Unsupervised Anomaly Detection for Industry Cybersecurity Operations
No full textreservedIn this thesis, we analyze an industry network traffic dataset containing hundreds of sensitive services related to the infrastructure of an oil and gas company. The main objective is to detect possible network and cybersecurity operations events resulting from behavioural changes in unlabelled data. Indeed, given the real-world nature of the studied dataset, no labels are found in the data, and we work in an unsupervised learning framework. We implement an automatic detection system for server and user traffic behavioural changes. We proactively detect long-term, subtle events with an observation window spanning a complete user work shift of eight hours. We start our research by grounding our intuition in server data's relatively less complex context. In particular, we perform clustering on some feature-space and try to characterize the server data with a Hidden Markov Model. Then, after exploring the difficulty of automatically learning a discrete Markov chain representation for the user data, we resort to field-expert estimations of state thresholds. There, we analyze the case of independent univariate state representations for each metric under observation and the case of a single multivariate state representation. While the first approach allows for the detection of uncharacteristic path probabilities for each metric independently, the second, multivariate, approach considers all metrics simultaneously such that not only unlikely state transitions may be detected, but also the presence of rare multivariate states. Finally, the system provides a ranking of user IP addresses behavioural change scores, allowing network administrators to plan their work capacity more efficiently.In this thesis, we analyze an industry network traffic dataset containing hundreds of sensitive services related to the infrastructure of an oil and gas company. The main objective is to detect possible network and cybersecurity operations events resulting from behavioural changes in unlabelled data. Indeed, given the real-world nature of the studied dataset, no labels are found in the data, and we work in an unsupervised learning framework. We implement an automatic detection system for server and user traffic behavioural changes. We proactively detect long-term, subtle events with an observation window spanning a complete user work shift of eight hours. We start our research by grounding our intuition in server data's relatively less complex context. In particular, we perform clustering on some feature-space and try to characterize the server data with a Hidden Markov Model. Then, after exploring the difficulty of automatically learning a discrete Markov chain representation for the user data, we resort to field-expert estimations of state thresholds. There, we analyze the case of independent univariate state representations for each metric under observation and the case of a single multivariate state representation. While the first approach allows for the detection of uncharacteristic path probabilities for each metric independently, the second, multivariate, approach considers all metrics simultaneously such that not only unlikely state transitions may be detected, but also the presence of rare multivariate states. Finally, the system provides a ranking of user IP addresses behavioural change scores, allowing network administrators to plan their work capacity more efficiently
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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