305,188 research outputs found
Interazioni Umane in Cybersecurity: Minacce e Opportunità
No full textNel corso degli anni, molte violazioni della sicurezza informatica sono state attribuite all'errore umano, considerando i fattori umani come uno degli anelli più deboli della catena della sicurezza. Nella pratica, i fattori umani vengono sfruttati dai criminali informatici, causando significative perdite di denaro e di reputazione alle organizzazioni. Secondo il Data Breach Investigations report 2021 di Verizon, l'85% delle violazioni ha coinvolto un elemento umano, mentre il 61% ha coinvolto credenziali rubate o compromesse, causando un costo medio di violazione di più di 3 milioni di dollari.
Per prevenire i cyberattacchi, le organizzazioni si concentrano sulla formazione dei dipendenti e sullo sviluppo di nuove policy, cercando anche di mantenere un equilibrio tra la complessità dei sistemi di sicurezza e la loro usabilità. Tuttavia, l'imprevedibilità del comportamento umano, la rapida evoluzione del mondo digitale e la crescente disponibilità di risorse tecnologiche per i criminali informatici pongono nuove sfide sia nell'anticipare le minacce informatiche in nuovi ambienti, sia per l’insorgere di nuove minacce nei sistemi considerati sicuri fino ad oggi.
D'altra parte, la complessità e l'unicità del comportamento umano aprono possibilità per la progettazione di nuove soluzioni per mitigare le minacce, migliorando la sicurezza delle organizzazioni e degli utenti.
In questa tesi, indaghiamo le interazioni umane e la sicurezza informatica, concentrandoci su due aspetti principali: (i) lo sviluppo di nuovi attacchi, basati sull'interazione umana, contro metodi di autenticazione esistenti e consolidati (PIN pad), e (ii) la proposta di nuovi metodi che sfruttano il comportamento umano in diversi contesti per migliorare la sicurezza degli utenti e delle organizzazioni.
La prima parte di questa tesi, dimostra l'efficacia di tre attacchi contro la sicurezza dei sistemi di autenticazione basati sul PIN, concentrandosi sui PIN pad degli Automated Teller Machines (ATM). Gli ATM sono diventati una parte indispensabile dell'ecosistema bancario tanto che, secondo la Banca Centrale Europea, nel 2019 solo in Europa sono state effettuate più di 11 miliardi di operazioni di prelievo e deposito.
In particolare, mostriamo come i PIN pad degli ATM siano esposti a minacce di sicurezza legate a fattori umani anche se gli utenti hanno comportamenti conformi alle policy. Analizziamo diversi scenari di attacco a seconda delle fonti di informazione disponibili per l'attaccante (ad esempio, video, audio, termico, stile di digitazione). I risultati mostrano che nello scenario peggiore per la vittima, i nostri attacchi possono ricostruire fino al 94% dei PIN a 5 cifre digitati entro tre tentativi.
Nella seconda parte di questa tesi, mostriamo come la variabilità e l'imprevedibilità del comportamento umano possano essere sfruttate per aumentare la sicurezza dei sistemi e degli utenti.
Sviluppiamo nuovi approcci human-based concentrandoci su tre diversi contesti: (i) nuovi metodi per il rilevamento dei bot nei social network (ad esempio, Twitter) basati sulla coerenza stilistica dei post nel tempo, (ii) un nuovo framework per identificare espressioni false e genuine dai video, e (iii) un nuovo metodo di de-autenticazione basato sul rilevamento di volti fisicamente sfocati. I risultati dimostrano l'efficacia degli approcci proposti, raggiungendo un F1-score fino al 98% nella classificazione dell'uomo-bot, un'accuratezza fino al 90% nell'individuazione della tristezza fasulla, e un'accuratezza nella de-autenticazione degli utenti fino al 100% sotto 3 secondi di periodo di grazia.
Questa tesi evidenzia la necessità di maggiori sforzi nella progettazione di soluzioni di sicurezza che si concentrino sui fattori umani, mostrando la direzione per ulteriori indagini nell'analisi delle interazioni umane nella cybersecurity.Over the years, many cybersecurity breaches have been attributed to human error, considering human factors as one of the weakest links in the security chain. In fact, human factors are exploited by cybercriminals, causing significant losses of money and reputation to organizations. According to Verizon's 2021 Data Breach Investigations, 85% of breaches involved a human element, while 61% involved stolen or compromised credentials, causing an average breach cost of more than $3 million.
To prevent cyberattacks, organizations focus on training employees and developing new policies, while also trying to maintain a balance between the complexity of security systems and their usability. However, the unpredictability of human behavior, the fast evolution of the digital world, and the increasing availability of technological resources for cybercriminals pose new and evolving cybersecurity challenges in anticipating both cyber threats in new environments and the rise of new threats in systems considered secure to date.
On the other hand, the complexity and uniqueness of human behavior give new opportunities for designing new solutions to mitigate threats, improving the security of organizations and users.
In this thesis, we investigate human interactions and cybersecurity, focusing on two main aspects: (i) developing new attacks, based on human interaction, against existing and consolidated authentication methods (i.e., PIN pads), and (ii) proposing new methods leveraging human behavior in multiple contexts to enhance the security of users and organizations.
The first part of this thesis demonstrates the effectiveness of three attacks against the security of PIN-based authentication systems, focusing on Automated Teller Machines (ATMs) PIN pads. ATMs have become an indispensable part of the banking ecosystem such that according to the European Central Bank, in 2019 only in Europe, more than 11 billion withdrawal and deposit transactions were made.
In particular, we show how ATM PIN pads are exposed to security threats related to human factors even if users have policy-compliant behaviors. We analyze different attack scenarios depending on the sources of information available to the attacker (e.g., video, audio, thermal, typing style). The results show that in the worst-case scenario for the victim, our attacks can reconstruct up to 94% of the 5-digit PINs typed within three attempts.
In the second part of this thesis, we show how the variability and unpredictability of human behavior can be exploited to increase the security of systems and users.
We develop new human-based approaches focusing on three different contexts: (i) new methods for bot detection in social networks (i.e., Twitter) relying on the stylistic consistency of posts over time, (ii) a new framework for identifying fake and genuine expressions from videos, and (iii) a new de-authentication method based on the detection of physically blurred faces. Results demonstrate the efficacy of the proposed approaches, achieving an F1-score up to 98% in human-bot detection, an accuracy up to 90% in fake sadness detection, and accuracy in de-authenticating users up to 100% under 3 seconds of grace period.
This thesis highlights the need for more effort in designing security solutions that focus on human factors, showing the direction for further investigation in analyzing human interactions in cybersecurity
High frequency of OPA1 mutations causing high ADOA prevalence in south-eastern Sicily, Italy.
No full textGallus GN, Cardaioli E, Rufa A, Collura M, Da Pozzo P, Pretegiani E, Tumino M, Pavone L, Federico A. High frequency of OPA1 mutations causing high ADOA prevalence in south-eastern Sicily, Italy. Optic atrophy type 1 (OPA1) gene mutation causes autosomal dominant optic atrophy (ADOA, MIM #165500). Prevalence of ADOA ranges from 1:50,000 in most populations to 1:12,000 in Denmark. Seventy members of nine families were analysed for the presence of OPA1 gene mutations by polymerase chain reaction (PCR) and direct sequencing. We identified three OPA1 gene mutations in 48 patients with variable signs of optic atrophy. Two mutations, c.784-21_784-22insAluYb8 and c.876_878delTGT, were found in two different families. The third mutation, c.869G>A, was found in 28 patients from seven families. The haplotype analysis data suggested that the c.869G>A mutation is a founder mutation. Our main result suggests a higher ADOA prevalence in south-eastern Sicily than previously found in Denmark. This is because of not only the founder effect but also to the presence of three different mutations in the geographical area of the study. Our hypothesis is that a combination of social pressure because of blindness and migration factors is involved. In fact, in Siracusa, a provincial capital in south-eastern Sicily, St. Lucy, the patron saint of the blind was born and died
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Mild hyperhomocyst(e)inemia: A possible risk factor for cervical artery dissection
No full textBackground and Purpose—The pathogenesis of cervical artery dissection (CAD) remains unknown in most cases.
Hyperhomocyst(e)inemia [hyperH(e)], an independent risk factor for cerebrovascular disease, induces damage in
endothelial cells in animal cell culture. Consecutive patients with CAD and age-matched control subjects have been
studied by serum levels of homocyst(e)ine and the genotype of 5,10-methylenetetrahydrofolate reductase (MTHFR).
Methods—Twenty-six patients with CAD, admitted to our Stroke Unit (15 men and 11 women; 16 vertebral arteries, 10
internal carotid arteries), were compared with age-matched control subjects. All patients underwent duplex ultrasound,
MR angiography, and/or conventional angiography.
Results—Mean plasma homocyst(e)ine level was 17.88 mmol/L (range 5.95 to 40.0 mmol/L) for patients with CAD and
6.060.99 mmol/L for controls (P,0.001). The genetic analysis for the thermolabile form of MTHFR in CAD patients
showed heterozygosity in 54% and homozygosity in 27%; comparable figures for controls were 40% (P50.4) and 10%
(P50.1), respectively.
Conclusions—Mild hyperH(e) might represent a risk factor for cervical artery dissection. The MTHFR mutation is not
significantly associated with CAD. An interaction between different genetic and environmental factors probably takes
place in the cascade of pathogenetic events leading to arterial wall damage.Background and Purpose - The pathogenesis of cervical artery dissection (CAD) remains unknown in most cases. Hyperhomocyst(e)inemia [hyperH(e)], an independent risk factor for cerebrovascular disease, induces damage in endothelial cells in animal cell culture. Consecutive patients with CAD and age-matched control subjects have been studied by serum levels of homocyst(e)ine and the genotype of 5,10-methylenetetrahydrofolate reductase (MTHFR). Methods - Twenty-six patients with CAD, admitted to our Stroke Unit (15 men and 11 women; 16 vertebral arteries, 10 internal carotid arteries), were compared with age-matched control subjects. All patients underwent duplex ultrasound, MR angiography, and/or conventional angiography. Results - Mean plasma homocyst(e)ine level was 17.88 μmol/L (range 5.95 to 40.0 μmol/L) for patients with CAD and 6.0±0.99 μmol/L for controls (P<0.001). The genetic analysis for the thermolabile form of MTHFR in CAD patients showed heterozygosity in 54% and homozygosit..
Sequence analysis of the complete mitochondrial genome in patients with mitochondrial encephaloneuromyopathies lacking the common pathogienic DNA mutations
No full textThe purpose of this study was to identify novel mitochondrial deoxyribonucleic acid (mtDNA) mutations in a series of patients with clinical and/or morphological features of mitochondrial dysfunction, but still no genetic diagnosis. A heterogeneous group of clinical disorders is caused by mutations in mtDNA that damage respiratory chain function of cell energy production. We developed a method to systematically screen the entire mitochondrial genome. The sequence-data were obtained with a rapid automated system. In the six mitochondrial genomes analysed we found 20 variants of the revised Cambridge reference sequence [Nat. Genet. 23 (1999) 147]. In skeletal muscle nineteen novel mtDNA variants were homoplasmic, suggesting secondary pathogenicity or co-responsibility in determination of the disease. In one patient we identified a novel heteroplasmic mtDNA mutation which presumably has a pathogenic role. This screening is therefore useful to extend the mtDNA polymorphism database and should facilitate definition of disease-related mutations in human mtDN
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Evidence of apoptosis via TUNEL staining in muscle biopsy from patients with mitochondrial encephaloneuromyopathies
No full textApoptosis is an evolution-conserved form of cell death essential for development and maintenance of tissue homeostasis. Dysregulation of apoptosis has been implicated in several pathological conditions, including neurodegenerative disorders. The crucial role of mitochondria in regulation of the apoptotic pathway prompted us to investigate the pattern of apoptosis in muscle biopsies from 17 patients with mitochondrial encephaloneuromyopathies caused by mtDNA defects. The results were compared with muscle biopsies from controls and from patients with myopathies without mitochondrial impairment. The terminal deoxynucleotidyl transferase-mediated dUTP nick and labelling (TUNEL) reaction was used as marker of apoptosis. Our findings were very heterogeneous, even between patients with the same mtDNA mutations, suggesting that tissue evaluation of apoptotic process is less useful than in vitro techniques, for investigating the role of apoptosis in mitochondrial pathologies
Studies on mitochondrial pathogenesis of Rett syndrome: ultrastructural data from skin and muscle biopsies and mutational analysis at mtDNA nucleotides 10463 and 2835
No full textIn order to verify the pathogenic role of mitochondria in Rett syndrome, the results are reported of skin and muscle biopsies in two RS patients, showing morphological ultrastructural abnormalities in mitochondrial number and size. The investigation on two recently described mtDNA mutations (at nt 10463 and 2835) (Lewis et al., 1995; Tang et al., 1997) gave contrasting results with respect to previously reported data. In particular, the first mutation has been found in seven subjects, five of whom were from two different control groups, while the second mutation has been not detected in any of the 26 patients and controls. Although these results present some signs of a morphological impairment of mitochondria, they do not support the hypothesis that the two mutations may have a primary role in the pathogenesis of the syndrome and indicate the need for further investigations on the role of mtDNA in the pathogenesis of the syndrome
Long-term nasal intermittent positive pressure ventilation in advanced Duchenne's muscular dystrophy
No full textThe aim of our study was to evaluate the long-term effect of nasal ventilation in patients with advanced Duchenne's muscular dystrophy (DMD). To this end, we compared the clinical and pulmonary function course of five subjects affected with chronic ventilatory failure due to DMD and treated with nasal intermittent positive pressure ventilation (NIPPV) with that of an unventilated comparison group; the latter consisted of another five patients with DMD, with a similar degree of clinical and respiratory functional impairment, who refused long-term mechanical ventilation. The duration of the follow-up was 24 months. At the conclusion of the trial, all patients treated with NIPPV were still alive; in contrast, four of five patients who underwent simple conservative treatment had already died (mean survival, 9.7 +/- 5.8 months). After 6 months of follow-up, mean loss of FVC and maximal voluntary ventilation was considerably higher in nonventilated subjects (respectively: -0.23 L vs +0.03 L and -5 L/min vs -1.5 L/min). These are the first comparative results confirming that long-term NIPPV helps to stabilize pulmonary function and to prolong the expectancy of life of patients with DMD
Author, publisher and bookseller : a tripartite synergy in Nigerian book industry
No full textThis work is about the roles of Author, Publisher and Bookseller in Book development in
Nigeria. The paper started by delving into the history of Book Publishing in Nigeria after
which it proceeded by defining who an author, a publisher, and a bookseller is and
expatiated on the indispensable roles of these key actors in Nigerian Book Industry and in
the emerging Information Society. Furthermore, the various constraints to book
development were identified while the paper advised on how the Book Industry can be
further promoted in Nigeria. However, the paper concluded and made recommendations
on how the Book sector can help in enhancing scholarship in the country
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