787 research outputs found
SUTMS - Unified Threat Management Framework for Home Networks
Home networks were initially designed for web browsing and non-business critical applications. As infrastructure improved, internet broadband costs decreased, and home internet usage transferred to e-commerce and business-critical applications. Today’s home computers host personnel identifiable information and financial data and act as a bridge to corporate networks via remote access technologies like VPN. The expansion of remote work and the transition to cloud computing have broadened the attack surface for potential threats. Home networks have become the extension of critical networks and services, hackers can get access to corporate data by compromising devices attacked to broad- band routers. All these challenges depict the importance of home-based Unified Threat Management (UTM) systems. There is a need of unified threat management framework that is developed specifically for home and small networks to address emerging security challenges. In this research, the proposed Smart Unified Threat Management (SUTMS) framework serves as a comprehensive solution for implementing home network security, incorporating firewall, anti-bot, intrusion detection, and anomaly detection engines into a unified system. SUTMS is able to provide 99.99% accuracy with 56.83% memory improvements. IPS stands out as the most resource-intensive UTM service, SUTMS successfully reduces the performance overhead of IDS by integrating it with the flow detection mod- ule. The artifact employs flow analysis to identify network anomalies and categorizes encrypted traffic according to its abnormalities. SUTMS can be scaled by introducing optional functions, i.e., routing and smart logging (utilizing Apriori algorithms). The research also tackles one of the limitations identified by SUTMS through the introduction of a second artifact called Secure Centralized Management System (SCMS). SCMS is a lightweight asset management platform with built-in security intelligence that can seamlessly integrate with a cloud for real-time updates
Mayhem: Targeted Corruption of Register and Stack Variables
In the past decade, many vulnerabilities were discovered in
microarchitectures which yielded attack vectors and motivated the study of
countermeasures. Further, architectural and physical imperfections in DRAMs led
to the discovery of Rowhammer attacks which give an adversary power to
introduce bit flips in a victim's memory space. Numerous studies analyzed
Rowhammer and proposed techniques to prevent it altogether or to mitigate its
effects.
In this work, we push the boundary and show how Rowhammer can be further
exploited to inject faults into stack variables and even register values in a
victim's process. We achieve this by targeting the register value that is
stored in the process's stack, which subsequently is flushed out into the
memory, where it becomes vulnerable to Rowhammer. When the faulty value is
restored into the register, it will end up used in subsequent iterations. The
register value can be stored in the stack via latent function calls in the
source or by actively triggering signal handlers. We demonstrate the power of
the findings by applying the techniques to bypass SUDO and SSH authentication.
We further outline how MySQL and other cryptographic libraries can be targeted
with the new attack vector. There are a number of challenges this work
overcomes with extensive experimentation before coming together to yield an
end-to-end attack on an OpenSSL digital signature: achieving co-location with
stack and register variables, with synchronization provided via a blocking
window. We show that stack and registers are no longer safe from the Rowhammer
attack
LIPIcs, Volume 261, ICALP 2023, Complete Volume
LIPIcs, Volume 261, ICALP 2023, Complete Volum
Using experiment and first-principles to explore the stability of solid electrolytes for all-solid-state lithium batteries
Cotutelle entre l'Université de Montréal et l'Université catholique de LouvainLes batteries aux ions lithium (BIL) sont considérées comme la technologie la plus prometteuse en matière de stockage d’énergie. Elles possèdent les plus hautes densités d’énergie connues, permettant la miniaturisation constante des appareils électroniques commercialisés. La recherche dans le domaine des BIL s’est plus récemment tournée vers leur implémentation dans les véhicules électriques, qui nécessitera de plus hautes densités d’énergie et de puissance . Une manière concrète d’augmenter la densité d’énergie d’une BIL est d’en augmenter le voltage de cellule. Pour se faire, la nouvelle génération de batteries sera composée de matériaux d’électrode positive à haut potentiel (tel que LiMn1.5Ni0.5O4 avec un potentiel de 4.7 V vs. Li+ /Li) et de lithium métallique en électrode négative. Néanmoins, l’introduction de ces matériaux d’électrode positive à haut potentiel est limitée par la stabilité électrochimique de l’électrolyte liquide conventionnel, composé d’un sel de lithium et de solvants organiques (typiquement LiPF6 + EC/DEC), qui s’oxyde autour de 4.2 V vs. Li+/Li , . L’utilisation du lithium métallique comme électrode négative est entravée par la nature liquide de l’électrolyte conventionnel, qui n’offre pas assez de résistance mécanique pour empêcher la formation de dendrites de lithium, causant à terme le court-circuit de la batterie. De tels courts-circuits présentent un risque d’incendie car les électrolytes liquides sont composés de solvants organiques inflammables à basse température, posant un sérieux problème de sécurité.
Les électrolytes solides, de type céramique ou polymères, sont développés en alternative aux électrolytes liquides. Ils ne contiennent aucun solvant inflammable et sont stables à haute température. Ils constituent l’élément clé d’une nouvelle génération de batteries au lithium dite batteries au lithium tout-solide. Ces dernières sont développées pour répondre à des attentes élevées en termes de sécurité, de stabilité et de haute densité d’énergie. Les électrolytes solides doivent satisfaire un certain nombre d'exigences avant de pouvoir être commercialisés, notamment posséder une conductivité ionique élevée, une large fenêtre de stabilité électrochimique et une conductivité électronique négligeable. Ces propriétés constituent les critères les plus importants à prendre en compte pour la sélection de matériaux d’électrolytes solides. Cependant, on remarque dans la littérature que la majorité des études se concentre sur la conductivité ionique des électrolytes solides, reléguant au second plan l’exploration de leurs stabilité électrochimique et conductivité électronique. La fenêtre de stabilité électrochimique a longtemps été annoncée comme étant très large chez les électrolytes solides céramiques (au moins de 0 à 5 V vs. Li+/Li). Néanmoins, des études plus récentes tendent à démontrer que la valeur de cette fenêtre dépend grandement de la méthode électrochimique utilisée pour la mesurer, et qu’elle est de surcroit souvent surestimée. Dans ce contexte, le premier objectif de cette thèse a été de développer une méthode pertinente pour déterminer la fenêtre de stabilité des électrolytes solides avec précision. Cette méthode a été optimisée et validée sur des électrolytes solides céramiques phare comme Li1.5Al0.5Ge1.5(PO4)3, Li1.3Al0.3Ti1.7(PO4)3 et Li7La3Zr2O12. Quant à la conductivité électronique, elle est rarement étudiée dans les électrolytes solides, qui sont considérés comme isolants électroniques compte tenu de leur large bande interdite. Cela dit, de récentes études à ce sujet prouvent que malgré leur bande interdite, les électrolytes solides peuvent générer de la conductivité électronique par le biais de défauts, et que celle-ci, même faible, peut éventuellement mettre l’électrolyte en échec. Pour cette raison, le second objectif de ce projet de thèse a été d’explorer la formation de défauts dans les électrolytes solides afin de déterminer leur effet sur la génération de conductivité électronique. Pour avoir une vision d’ensemble, les premiers-principes ont été utilisés pour étudier six électrolytes solides largement utilisés notamment LiGe2(PO4)3, LiTi2(PO4)3, Li7La3Zr2O12, et Li3PS4.Lithium-ion batteries (LIBs) are considered the most promising energy storage technology. LIBs electrode materials have the highest known energy densities, allowing the constant miniaturization of commercial electronic devices. Research in the field of LIBs has more recently turned to their implementation in electric vehicles, which will require higher energy and power densities . A concrete way to increase the energy density of LIBs is to increase the cell voltage. To do so, the new generation of batteries will be composed of high potential positive electrode materials (such as LiMn1.5Ni0.5O4 with a potential of 4.7 V vs. Li+/Li) and metallic lithium in the negative electrode. Nevertheless, the introduction of these high potential positive electrode materials is limited by the electrochemical stability of conventional liquid electrolytes, composed of a lithium salt and organic solvents (LiPF6 + EC/DEC), which gets oxidized around 4.2 V vs. Li+/Li , . The use of metallic lithium as the negative electrode is also hindered by the liquid nature of the conventional electrolyte, which does not offer enough mechanical resistance to prevent the formation of lithium dendrites, ultimately causing a short-circuit of the battery. Such short-circuits are likely to lead to thermal runaway because liquid electrolytes are composed of organic solvents that are flammable at low temperature, posing a serious safety issue.
Solid electrolytes, based on ceramics or polymers, are developed as an alternative to liquid electrolytes. They contain no flammable solvents and are stable at high temperatures. They are the key element of a new generation of lithium batteries called all-solid-state lithium batteries. These are developed to meet high expectations in terms of safety, stability and high energy density. Solid electrolytes must satisfy a number of requirements before they can be commercialized, including possessing a high ionic conductivity, a wide electrochemical stability window and negligible electronic conductivity. These properties are the most important criteria to consider when selecting solid electrolyte materials. However, the majority of studies found in the literature focuses on the ionic conductivity of solid electrolytes, overshadowing the exploration of their electrochemical stability and electronic conductivity. The electrochemical stability window has long been reported to be very wide in ceramic solid electrolytes (at least from 0 to 5 V vs. Li+/Li). Nevertheless, more recent studies tend to show that the value of this window depends greatly on the electrochemical method used to measure it, and that it is often overestimated. In this context, the first objective of this thesis was to develop a relevant method to determine the stability window of solid electrolytes with precision. This method was optimized and validated on flagship ceramic solid electrolytes such as Li1.5Al0.5Ge1.5(PO4)3, Li1.3Al0.3Ti1.7(PO4)3 and Li7La3Zr2O12. As for the electronic conductivity, it is scarcely studied in solid electrolytes, which are considered as electronic insulators given their wide band gaps. That being said, more recent studies on this subject proved that despite their band gap, solid electrolytes can generate electronic conductivity through defects, and that electronic conductivity, even if it is weak, can eventually cause the failure of the electrolyte. For this reason, the second objective of this thesis project was to explore the formation of defects in solid electrolytes in order to determine their effect on the generation of electronic conductivity. To get a better overview, first-principles were used to investigate six widely used ceramic solid electrolytes, including LiGe2(PO4)3, LiTi2(PO4)3, Li7La3Zr2O12, and Li3PS4
CNN-based Prediction of Partition Path for VVC Fast Inter Partitioning Using Motion Fields
The Versatile Video Coding (VVC) standard has been recently finalized by the
Joint Video Exploration Team (JVET). Compared to the High Efficiency Video
Coding (HEVC) standard, VVC offers about 50% compression efficiency gain, in
terms of Bjontegaard Delta-Rate (BD-rate), at the cost of a 10-fold increase in
encoding complexity. In this paper, we propose a method based on Convolutional
Neural Network (CNN) to speed up the inter partitioning process in VVC.
Firstly, a novel representation for the quadtree with nested multi-type tree
(QTMT) partition is introduced, derived from the partition path. Secondly, we
develop a U-Net-based CNN taking a multi-scale motion vector field as input at
the Coding Tree Unit (CTU) level. The purpose of CNN inference is to predict
the optimal partition path during the Rate-Distortion Optimization (RDO)
process. To achieve this, we divide CTU into grids and predict the Quaternary
Tree (QT) depth and Multi-type Tree (MT) split decisions for each cell of the
grid. Thirdly, an efficient partition pruning algorithm is introduced to employ
the CNN predictions at each partitioning level to skip RDO evaluations of
unnecessary partition paths. Finally, an adaptive threshold selection scheme is
designed, making the trade-off between complexity and efficiency scalable.
Experiments show that the proposed method can achieve acceleration ranging from
16.5% to 60.2% under the RandomAccess Group Of Picture 32 (RAGOP32)
configuration with a reasonable efficiency drop ranging from 0.44% to 4.59% in
terms of BD-rate, which surpasses other state-of-the-art solutions.
Additionally, our method stands out as one of the lightest approaches in the
field, which ensures its applicability to other encoders
PENGARUH FITUR LAYANAN, KEAMANAN DAN KEMUDAHAN PENGGUNAAN E-WALLET TERHADAP TRANSAKSI MAHASISWA MENGGUNAKAN E-WALLET APLIKASI DANA (Studi Pada Mahasiswa UIN RIL Fakultas Ekonomi dan Bisnis Islam)
ABSTRAK
Perkembangan teknologi yang semakin pesat mendorong
adanya kompetisi yang ketat di dunia bisnis dan mendominasi
aktivitas manusia yang mempermudah kegiatan seperti penggunaan e�wallet sebagai alat pembayaran atau transaksi yang meningkat sejak
pandemi Covid-19 yang diumumkan pemerintah pada bulan maret
2020 lalu dikarenakan adanya dampak pandemi covid-19 dimana
segala aktivitas dilakukan secara online. E-wallet aplikasi DANA
berhasil memperoleh peringkat pertama e-wallet yang paling banyak
diketahui masyarakat Indonesia. Rumusan masalah pada penelitian ini
yaitu apakah fitur layanan, keamanan dan kemudahan penggunaan e�wallet baik secara parsial maupun simultan berpengaruh signifikan
terhadap transaksi mahasiswa Fakultas Ekonomi dan Bisnis Islam
UIN RIL menggunakan e-wallet aplikasi DANA dalam perspektif
ekonomi Islam. Berdasarkan rumusan masalah, penelitian ini
bertujuan untuk mengetahui pengaruh fitur layanan, keamanan dan
kemudahan penggunaan e-wallet terhadap transaksi mahasiswa
menggunakan e-wallet aplikasi DANA baik secara parsial maupun
simultan dan dalam perspektif ekonomi Islam.
Penelitian ini menggunakan metode pendekatan kuantitatif.
Penelitian kuantitatif dengan menggunakan metode pengujian
statistik. Jenis data yang digunakan dalam penelitian ini adalah data
primer dengan menyebarkan kuesioner melalui google form. Populasi
pada penelitian ini yaitu sebanyak 1165 mahasiswa dan sampel yang
diambil menggunakan metode purposive sampling sebanyak 92
responden. Metoode analisis data yang digunakan adalah analisis
regresi linier berganda dengan menggunakan program IBM SPSS
Versi 25.
Hasil penelitian menunjukkan bahwa variabel fitur layanan
(X1), keamanan (X2) dan kemudahan penggunaan (X3) berpengaruh
signifikan terhadap transaksi mahasiswa mengunakan e-wallet aplikasi
DANA baik secara parsial maupun simultan dan dalam perspektif
ekonomi Islam.
Kata kunci : Fitur Layanan, Keamanan, Kemudahan Penggunaan,
Transaksi menggunakan e-wallet aplikasi DANA.
ABSTRACT
The rapid development of technology encourages intense
competition in the business world and dominates human activities that
facilitate activities such as the use of e-wallets as a means of payment
or transactions that have increased since the Covid-19 pandemic
which was announced by the government in March 2020 due to the
impact of the covid pandemic -19 where all activities are carried out
online. The DANA application e-wallet has succeeded in obtaining the
first rank of e-wallet that is most widely known by the people of
Indonesia. The formulation of the problem in this study is whether
service features, security, and ease of use of e-wallets either partially
or simultaneously have a significant effect on student transactions of
the Faculty of Economics and Business of Islam UIN RIL using the
DANA application e-wallet in an Islamic economic perspective. Based
on the formulation of the problem, this study aims to determine the
effect of service features, security, and ease of use of e-wallets on
student transactions using the DANA application e-wallet both
partially and simultaneously and from an Islamic economic
perspective.
This study uses a quantitative approach method. Quantitative
research using statistical testing methods. The type of data used in this
study is primary data by distributing questionnaires via Google
Forms. The population in this study was 1165 students and samples
taken using the purposive sampling method were 92 respondents. The
data analysis method used is multiple linear regression analysis using
the IBM SPSS Version 25 program.
The results of the study show that the variable service features
(X1), security (X2), and ease of use (X3) have a significant effect on
student transactions using the DANA application e-wallet both
partially and simultaneously and in an Islamic economic perspective.
Keywords: Service Features, Security, Ease of Use, Transactions
using the DANA application e-wallet
The Breakup of the Bell System and its Impact on US Innovation
We analyze the effects of the 1984 breakup of the Bell System on the rate, diversity, and direction of US innovation. In the antitrust case leading to the breakup, AT&T, the holding company of the Bell System, was accused of using exclusionary practices against competitors. The breakup was intended to end these practices. After the breakup, the scale and diversity of telecommunications innovation increased. Total patenting by US inventors related to telecommunications increased by 19%, driven by companies unrelated to the Bell System. Patenting by Bell's successor companies decreased, but not the number of top inventions
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