14 research outputs found
SLAP: Improving Physical Adversarial Examples with Short-Lived Adversarial Perturbations
Research into adversarial examples (AE) has developed rapidly, yet static
adversarial patches are still the main technique for conducting attacks in the
real world, despite being obvious, semi-permanent and unmodifiable once
deployed.
In this paper, we propose Short-Lived Adversarial Perturbations (SLAP), a
novel technique that allows adversaries to realize physically robust real-world
AE by using a light projector. Attackers can project a specifically crafted
adversarial perturbation onto a real-world object, transforming it into an AE.
This allows the adversary greater control over the attack compared to
adversarial patches: (i) projections can be dynamically turned on and off or
modified at will, (ii) projections do not suffer from the locality constraint
imposed by patches, making them harder to detect.
We study the feasibility of SLAP in the self-driving scenario, targeting both
object detector and traffic sign recognition tasks, focusing on the detection
of stop signs. We conduct experiments in a variety of ambient light conditions,
including outdoors, showing how in non-bright settings the proposed method
generates AE that are extremely robust, causing misclassifications on
state-of-the-art networks with up to 99% success rate for a variety of angles
and distances. We also demostrate that SLAP-generated AE do not present
detectable behaviours seen in adversarial patches and therefore bypass
SentiNet, a physical AE detection method. We evaluate other defences including
an adaptive defender using adversarial learning which is able to thwart the
attack effectiveness up to 80% even in favourable attacker conditions.Comment: 13 pages, to be published in Usenix Security 2021, project page
https://github.com/ssloxford/short-lived-adversarial-perturbation
STASH : Securing transparent authentication schemes using prover-side proximity verification
Peer reviewe
Left-sided lesions after anatomic repair of transposition of the great arteries, ventricular septal defect, and coarctation: Surgical factors
AbstractObjectiveThis study was undertaken to identify potential anatomic and surgical factors creating left-sided lesions, namely recoarctation of the aorta and neoaortic regurgitation, after anatomic repair of transposition of the great arteries with ventricular septal defect and aortic coarctation.MethodsFrom 1983 to September 2002, 109 survivors out of 120 patients were studied. Two-stage repair was performed in 42 patients (group A), and single-stage repair was performed in 67 (groups B and C). Before repair, the diameters of the ascending aorta and main pulmonary artery were measured. In the patients with single-stage repair, coarctation was repaired by extended end-to-end anastomosis in 35 patients (group B) and by pulmonary homograft patch augmentation in 32 patients (group C). The ventricular septal defect was closed through the pulmonary artery in 70 patients and through the right ventricle or atrium in 39 patients. The neoaorto-aortic discrepancy was treated by V-shaped resection of the posterior sinus of Valsalva in 7 cases, pulmonary homograft patch in 32 cases, and anterior splitting of the ascending aorta in all cases. Before discharge from the hospital, neoaortic root and ascending aorta diameters and aortic regurgitation grade were recorded. Neoaortic regurgitation progression and reintervention were the end points of follow-up (97.2 ± 61.2 months).ResultsEarly and late survivals were significantly better in group C (P < .001). Risk factors for neoaortic regurgitation at discharge by univariate analysis were single-stage repair (P < .05) and ventricular septal defect closure through the pulmonary artery (P = .0076). On multivariate analysis, the latter was the only risk factor for neoaortic regurgitation at discharge and at last follow-up. Multivariate analysis showed that higher neoaortic root/ascending aorta ratio and ventricular septal defect closure through the pulmonary artery were risk factors for neoaortic regurgitation evolution at last follow-up. There were 29 reinterventions, 19 for recoarctation of the aorta and 10 for neoaortic regurgitation with or without aortic root dilatation. Group B (P < .05), high neoaortic root/ascending aorta ratio (P < .01), and progressive neoaortic regurgitation (P < .05) were risk factors for recoarctation of the aorta. Group A was a risk factor for aortic valve replacement at 10 years (P < .05).ConclusionNeonatal single-stage repair with pulmonary homograft aortic augmentation remains the optimal approach to transposition of the great arteries with ventricular septal defect and aortic coarctation. It provides better early and late survivals and freedoms from left-sided lesions. Avoidance of late recoarctation of the aorta and progressive neoaortic regurgitation requires meticulous closure of the ventricular septal defect and evenly sized reconstruction of the aorta from root to distal arch
Surgical reconstruction of the left main coronary artery with patch-angioplasty
<p>Abstract</p> <p>Background</p> <p>Conventional coronary artery bypass grafting (CABG) has been established as the treatment of choice for left main coronary artery (LMCA) stenosis However, the conventional grafting provides a retrograde perfusion to extensive myocardial area and leads prospectively to competitive flow of the non-occluded coronaries thus consuming the grafts. Surgical reconstruction of the LMCA with patch-angioplasty is an alternative method that eliminates these drawbacks.</p> <p>Methods</p> <p>Between February 1997 and July 2007, 37 patients with isolated LMCA stenosis were referred for surgical ostial reconstruction. In 27 patients (73%) surgical angioplasties have been performed. All patients were followed up clinically and with transesophageal echocardiography (TEE) and coronary angiography when required.</p> <p>Results</p> <p>In 10 patients (27%) a LMCA stenosis could not be confirmed. There were no early mortality or perioperative myocardial infarctions. The postoperative course was uneventful in all patients. In 25 patients, TEE demonstrated a wide open main stem flow pattern one to six months after reconstruction of the left main coronary artery with one patch mild aneurysmal dilated.</p> <p>Conclusions</p> <p>The surgical reconstruction with patch-angioplasty is a safe and effective method for the treatment of proximal and middle LMCA stenosis. Almost one third of the study group had no really LMCA stenosis: antegrade flow pattern remained sustained and the arterial grafts have been spared. In the cases of unclear or suspected LMCA stenosis, cardio-CT can be performed to unmask catheter-induced coronary spasm as the underlying reason for isolated LMCA stenosis.</p
A Solve-RD ClinVar-based reanalysis of 1522 index cases from ERN-ITHACA reveals common pitfalls and misinterpretations in exome sequencing
Purpose
Within the Solve-RD project (https://solve-rd.eu/), the European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies aimed to investigate whether a reanalysis of exomes from unsolved cases based on ClinVar annotations could establish additional diagnoses. We present the results of the âClinVar low-hanging fruitâ reanalysis, reasons for the failure of previous analyses, and lessons learned.
Methods
Data from the first 3576 exomes (1522 probands and 2054 relatives) collected from European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies was reanalyzed by the Solve-RD consortium by evaluating for the presence of single-nucleotide variant, and small insertions and deletions already reported as (likely) pathogenic in ClinVar. Variants were filtered according to frequency, genotype, and mode of inheritance and reinterpreted.
Results
We identified causal variants in 59 cases (3.9%), 50 of them also raised by other approaches and 9 leading to new diagnoses, highlighting interpretation challenges: variants in genes not known to be involved in human disease at the time of the first analysis, misleading genotypes, or variants undetected by local pipelines (variants in off-target regions, low quality filters, low allelic balance, or high frequency).
Conclusion
The âClinVar low-hanging fruitâ analysis represents an effective, fast, and easy approach to recover causal variants from exome sequencing data, herewith contributing to the reduction of the diagnostic deadlock
Inferring user height and improving impersonation attacks in mobile payments using a smartwatch
In this paper, we show that as a user makes mobile payments with a smartwatch, the height of the user can be inferred purely from inertial sensor data captured on the watch (with R 2 scores of up to 0.77). Besides unwanted information exposure, we also show that users of a similar height are more difficult to distinguish between in terms of their tap gesture data and that an attacker who chooses a victim of a similar height can improve the success chance of impersonation (by increasing the false acceptance rate by up to 20.6%)
WatchAuth: user authentication and intent recognition in mobile payments using a smartwatch
In this paper, we show that the tap gesture, performed when a user âtapsâ a smartwatch onto an NFC-enabled terminal to make a payment, is a biometric capable of implicitly authenticating the user and simultaneously recognising intent-to-pay. The proposed system can be deployed purely in software on the watch without requiring updates to payment terminals. It is agnostic to terminal type and position and the intent recognition portion does not require any training data from the user. To validate the system, we conduct a user study (n=16) to collect wrist motion data from users as they interact with payment terminals and to collect long-term data from a subset of them (n=9) as they perform daily activities. Based on this data, we identify optimum gesture parameters and develop authentication and intent recognition models, for which we achieve EERs of 0.08 and 0.04, respectively
Businessplan Smart Sustainable cities
Uit voorwoord Anton Franken, lid CvB
`Smart Sustainable Cities is een platform voor het bedrijfsleven, kennisinstellingen
en Hogeschool Utrecht waar gezamenlijk vernieuwende
producten en diensten worden ontwikkeld die de realisatie van slimme,
duurzame en gezonde steden dichterbij brengt. Startende en ervaren
professionals hebben hiermee de mogelijkheid om via het onderwijs of
via bij- en nascholing de nieuwste toepasbare kennis en inzichten op dit
gebied op te doen. Tevens verricht het platform onderzoek. In projecten
werken studenten, bedrijven, docenten en onderzoekers samen om
nieuwe kennis en inzichten tot toepassing te brengen. Drie inhoudelijke
themaâs staan centraal: âStedelijke gebieden energieneutraalâ, âGezonde
gebieden gezond gebouwdâ en âDuurzaam gedrag: mens en organisatieâ .