25 research outputs found

    Speed reading in the dark : Accelerating functional encryption for quadratic functions with reprogrammable hardware

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    Functional encryption is a new paradigm for encryption where decryption does not give the entire plaintext but only some function of it. Functional encryption has great potential in privacy-enhancing technologies but suffers from excessive computational overheads. We introduce the first hardware accelerator that supports functional encryption for quadratic functions. Our accelerator is implemented on a reprogrammable system-on-chip following the hardware/software codesign methogol-ogy. We benchmark our implementation for two privacy-preserving machine learning applications: (1) classification of handwritten digits from the MNIST database and (2) classification of clothes images from the Fashion MNIST database. In both cases, classification is performed with encrypted images. We show that our implementation offers speedups of over 200 times compared to a published software implementation and permits applications which are unfeasible with software-only solutions.Peer reviewe

    Speed reading in the dark : Accelerating functional encryption for quadratic functions with reprogrammable hardware

    Get PDF
    Functional encryption is a new paradigm for encryption where decryption does not give the entire plaintext but only some function of it. Functional encryption has great potential in privacy-enhancing technologies but suffers from excessive computational overheads. We introduce the first hardware accelerator that supports functional encryption for quadratic functions. Our accelerator is implemented on a reprogrammable system-on-chip following the hardware/software codesign methogol-ogy. We benchmark our implementation for two privacy-preserving machine learning applications: (1) classification of handwritten digits from the MNIST database and (2) classification of clothes images from the Fashion MNIST database. In both cases, classification is performed with encrypted images. We show that our implementation offers speedups of over 200 times compared to a published software implementation and permits applications which are unfeasible with software-only solutions.Peer reviewe

    CAD Based Electric Transporter Path Planning and Production Storage Optimization Using Genetic Algorithm ā€“ Industrial Case Study

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    Å tore Steel Ltd. is one of the largest flat spring steel producers in Europe. There are two production lines after rolling ā€“ one for flat bars and the other for round bars. The flat bars production generally consists of visual examination, straightening and cutting operation. In addition, heat treatment or magnetic particle testing could be conducted. On the other hand, the round bars production consists generally of straightening, automatic control line control, chamfering and cutting. In addition, heat treatment is possible. For manipulation of the material in the rolling plant, the electric transporter and several cassettes are used. In the paper path planning and production storage optimization (i.e. storage spaces for cassettes) were conducted using genetic algorithm. The production storage is actually the space between main transport passage and individual operations. In the research the universal system using CAD geometry is presented where AutoCAD environment and in-house developed AutoLISP system were used. The production storage ā€“ storage spaces for cassettes (location and orientation) with corresponding electric transporter trajectories are represented as CAD objects and thus form individual solution/organism. The organisms undergo simulated evolution. The results of the evolution are compared with actual production storage in the steel plant

    Private Stream Aggregation from Labeled Secret Sharing Schemes

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    The concept of private stream aggregation (PSA) has been proposed by Shi et al. (NDSS 2011) to allow for data analysis in a privacy-preserving manner. In this work, we introduce the notion of labeled secret sharing (LaSS) schemes and show how to use it to construct PSA schemes. We also show how to realize LaSS using pseudorandom functions or alternatively with a hash function modeled as a random oracle and how it can be used to construct PSA schemes. Additionally, we revisit the security model of Becker et al. (NDSS 2018) and describe stronger security notions for PSA. We then present additional constructions achieving the stronger security notions by relying on recent results on multi-client functional encryption. For all of our constructions, we present implementations to show their practicality and the performance gains over existing solutions

    Analgesic efficacy of remifentanil patient-controlled analgesia versus combined spinal-epidural technique in multiparous women during labour

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    Objectives: To compare the analgesic profile of remifentanil patient-controlled analgesia (RPCA) and combined spinal-epidural analgesia technique (CSEA) in multiparous women during the entire labour. We hypothesized that CSEA would provide a better and more sustained pain reduction than RPCA.Material and methods: A prospective observational trial under ID NCT02963337 at a university hospital in Slovenia 2017ā€“2018. Analgesic efficacy, satisfaction with pain-relief, adverse effects, labour progress, and outcomes between RPCA (80) and CSEA (81) were compared.Results: CSEA provided significantly lower pain scores during the entire labour. Compared to baseline, significant pain reduction was recorded in both groups after 15 min. No difference was recorded compared to baseline with RPCA and CSEA after 45 and 90 mins, respectively. CSEA provided higher satisfaction than RPCA (5 [5ā€“5] vs 5 [4ā€“5], p < 0.0001). More patients with CSEA opted for the same technique for the next labour [CSEA; 77 (95%) vs RPCA; 65 (81%), p = 0.003]. No crossovers were observed. RPCA was associated with desaturation (34%), bradypnea (21%) and apnoea (25%), which were transitional and easily managed. None had severe sedation. No differences were recorded in labour progress and outcomes. Apgar scores were reassuring in all neonates (> 8). None had umbilical artery pH < 7.0.Conclusions: In multiparas, CSEA provided superior analgesia and satisfaction than RPCA. Nevertheless, RPCA provided a satisfactory experience, suggesting it could be used when neuraxial analgesia is not available, preferred, or contraindicated. In that case, constant presence of midwife is mandatory for management of clinically significant hypoventilation

    Improved algorithms for finding fixed-degree isogenies between supersingular elliptic curves

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    Finding isogenies between supersingular elliptic curves is a natural algorithmic problem which is known to be equivalent to computing the curves\u27 endomorphism rings. When the isogeny is additionally required to have a specific degree dd, the problem appears to be somewhat different in nature, yet it is also considered a hard problem in isogeny-based cryptography. Let E1,E2E_1,E_2 be supersingular elliptic curves over Fp2\mathbb{F}_{p^2}. We present improved classical and quantum algorithms that compute an isogeny of degree dd between E1E_1 and E2E_2 if it exists. Let the sought-after degree be d=p1/2+Ļµd = p^{1/2+ \epsilon} for some Ļµ>0\epsilon>0. Our essentially memory-free algorithms have better time complexity than meet-in-the-middle algorithms, which require exponential memory storage, in the range 1/2ā‰¤Ļµā‰¤3/41/2\leq\epsilon\leq 3/4 on a classical computer and quantum improvements in the range 0<Ļµ<5/20<\epsilon<5/2

    Pulmonary arterial hypertension diagnosed during pregnancy ā€“ echocardiography as a tool for management

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    Introduction: Despite advanced therapies for pulmonary arterial hypertension (PAH), maternal mortality in women with PAH and their offspring remains high (30-56% and 11-28%) and is especially high during the post-partum period1,2. Case report: 39-years-old woman was presented in 24th week of pregnancy with moderate dyspnea and cyanosis without peripheral edema. ECG showed right ventricular strain and NT-proBNP was 1300 ng/L. Echocardiogram showed severe precapillary pulmonary hypertension with systolic pulmonary pressure (PAP) 103 mmHg, reduced stroke volume (SVI 29 ml/m2), normal cardiac output (CI 2.6 L/min/m2) and mildly reduced systolic function of the right ventricle (FAC 30%, PMI TDI 0.8) with normal central venous pressure (CVP) 3 mmHg. Right heart catheterization confirmed echocardiographic hemodynamic measurements (mean pulmonary pressure 61 mmHg, pulmonary vascular resistance (PVR) 9.4 WU) and the vasoreactivity test was negative. Epoprostenol was initiated, titrated up to 22 ng/kg/min and on 30th week planned caesarean section was performed with NO inhalations, noradrenalin and dobutamine. Fortunately, standby supportive therapy - ECMO and high urgency lung transplantation, was not needed. The baby did well. The patient was extubated on the same day and sildenafil was added. The patient was discharged after 4 weeks. After 2 months epoprostenol was switched to treprostinil up to 26 ng/kg/min and macitentan was added. NT-proBNP stabilized at 170 ng/L. Echocardiography was performed weekly to monitor CI, CVP and right systolic function indexes. Favorable echocardiographic dynamics after therapy were observed: mean PAP 60 mmHg to 45-50 mmHg, PVR from 10 WU to 7 WU, stroke volume normalized and CVP remained normal. However, right ventricular systolic function improved but did not normalize (Table 1). In conclusion, with complete echocardiographic hemodynamic assessment and thorough clinical assessment high-risk pregnancies in patients with severe PAH can be managed. In addition, FAC, MPI TDI, 3D ejection fraction and RV free strain better assess right ventricular systolic function than TAPSE

    Intrapartum Cesarean Section and Perinatal Outcomes after Epidural Analgesia or Remifentanil-PCA in Breech and Twin Deliveries

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    Comparative data on the potential impact of various forms of labor analgesia on the mode of delivery and neonatal complications in vaginal deliveries of singleton breech and twin fetuses are lacking. The present study aimed to determine the associations between type of labor analgesia (epidural analgesia (EA) vs. remifentanil patient-controlled analgesia (PCA)) and intrapartum cesarean sections (CS), and maternal and neonatal adverse outcomes in breech and twin vaginal births. A retrospective analysis of planned vaginal breech and twin deliveries at the Department of Perinatology, University Medical Centre Ljubljana, was performed for the period 2013ā€“2021, using data obtained from the Slovenian National Perinatal Information System. The pre-specified outcomes studied were the rates of CS in labor, postpartum hemorrhage, obstetric anal sphincter injury (OASI), an Apgar score of <7 at 5 min after birth, birth asphyxia, and neonatal intensive care admission. A total of 371 deliveries were analyzed, including 127 term breech and 244 twin births. There were no statistically significant nor clinically relevant differences between the EA and remifentanil-PCA groups in any of the outcomes studied. Our findings suggest that both EA and remifentanil-PCA are safe and comparable in terms of labor outcomes in singleton breech and twin deliveries
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