CacheZoom: How SGX Amplifies The Power of Cache Attacks

In modern computing environments, hardware resources are commonly shared, and parallel computation is widely used. Parallel tasks can cause privacy and security problems if proper isolation is not enforced. Intel proposed SGX to create a trusted execution environment within the processor. SGX relies on the hardware, and claims runtime protection even if the OS and other software components are malicious. However, SGX disregards side-channel attacks. We introduce a powerful cache side-channel attack that provides system adversaries a high resolution channel. Our attack tool named CacheZoom is able to virtually track all memory accesses of SGX enclaves with high spatial and temporal precision. As proof of concept, we demonstrate AES key recovery attacks on commonly used implementations including those that were believed to be resistant in previous scenarios. Our results show that SGX cannot protect critical data sensitive computations, and efficient AES key recovery is possible in a practical environment. In contrast to previous works which require hundreds of measurements, this is the first cache side-channel attack on a real system that can recover AES keys with a minimal number of measurements. We can successfully recover AES keys from T-Table based implementations with as few as ten measurements.Comment: Accepted at Conference on Cryptographic Hardware and Embedded Systems (CHES '17

The Interaction of Genetic Mutations in PARK2 and FA2H Causes a Novel Phenotype in a Case of Childhood-Onset Movement Disorder

Mutations in the PARK2 gene have been implicated in the pathogenesis of early-onset Parkinson's disease. We present a case of movement disorder in a 4-year-old child from consanguineous parents and with a family history of Dopamine responsive dystonia, who was diagnosed with early-onset Parkinson's disease based on initial identification of a pathogenic PARK2 mutation. However, the evolution of the child's clinical picture was unusually rapid, with a preponderance of pyramidal rather than extrapyramidal symptoms, leading to re-investigation of the case with further imaging and genetic sequencing. Interestingly, a second homozygous mutation in the FA2H gene, implicated in Hereditary spastic paraplegia, was revealed, appearing to have contributed to the novel phenotype observed, and highlighting a potential interaction between the two mutated genes

How can frontline expertise and new models of care best contribute to safely reducing avoidable acute admissions? A mixed-methods study of four acute hospitals

Background: Hospital emergency admissions have risen annually, exacerbating pressures on emergency departments (EDs) and acute medical units. These pressures have an adverse impact on patient experience and potentially lead to suboptimal clinical decision-making. In response, a variety of innovations have been developed, but whether or not these reduce inappropriate admissions or improve patient and clinician experience is largely unknown. Aims: To investigate the interplay of service factors influencing decision-making about emergency admissions, and to understand how the medical assessment process is experienced by patients, carers and practitioners. Methods: The project used a multiple case study design for a mixed-methods analysis of decision-making about admissions in four acute hospitals. The primary research comprised two parts: value stream mapping to measure time spent by practitioners on key activities in 108 patient pathways, including an embedded study of cost; and an ethnographic study incorporating data from 65 patients, 30 carers and 282 practitioners of different specialties and levels. Additional data were collected through a clinical panel, learning sets, stakeholder workshops, reading groups and review of site data and documentation. We used a realist synthesis approach to integrate findings from all sources. Findings: Patients’ experiences of emergency care were positive and they often did not raise concerns, whereas carers were more vocal. Staff’s focus on patient flow sometimes limited time for basic care, optimal communication and shared decision-making. Practitioners admitted or discharged few patients during the first hour, but decision-making increased rapidly towards the 4-hour target. Overall, patients’ journey times were similar, although waiting before being seen, for tests or after admission decisions, varied considerably. The meaning of what constituted an ‘admission’ varied across sites and sometimes within a site. Medical and social complexity, targets and ‘bed pressure’, patient safety and risk, each influenced admission/discharge decision-making. Each site responded to these pressures with different initiatives designed to expedite appropriate decision-making. New ways of using hospital ‘space’ were identified. Clinical decision units and observation wards allow potentially dischargeable patients with medical and/or social complexity to be ‘off the clock’, allowing time for tests, observation or safe discharge. New teams supported admission avoidance: an acute general practitioner service filtered patients prior to arrival; discharge teams linked with community services; specialist teams for the elderly facilitated outpatient treatment. Senior doctors had a range of roles: evaluating complex patients, advising and training juniors, and overseeing ED activity. Conclusions: This research shows how hospitals under pressure manage complexity, safety and risk in emergency care by developing ‘ground-up’ initiatives that facilitate timely, appropriate and safe decision-making, and alternative care pathways for lower-risk, ambulatory patients. New teams and ‘off the clock’ spaces contribute to safely reducing avoidable admissions; frontline expertise brings value not only by placing senior experienced practitioners at the front door of EDs, but also by using seniors in advisory roles. Although the principal limitation of this research is its observational design, so that causation cannot be inferred, its strength is hypothesis generation. Further research should test whether or not the service and care innovations identified here can improve patient experience of acute care and safely reduce avoidable admissions. Funding: The National Institute for Health Research (NIHR) Health Services and Delivery Research programme (project number 10/1010/06). This research was supported by the NIHR Collaboration for Leadership in Applied Health Research and Care South West Peninsula

Randomised comparison of the effectiveness of the laryngeal mask airway supreme, i-gel and current practice in the initial airway management of out of hospital cardiac arrest: A feasibility study

© 2016 The Author. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. Background: The best initial approach to advanced airway management during out of hospital cardiac arrest (OHCA) is unknown. The traditional role of tracheal intubation has been challenged by the introduction of supraglottic airway devices (SGAs), but there is contradictory evidence from observational studies. We assessed the feasibility of a cluster-randomized trial to compare the i-gel SGA vs the laryngeal mask airway supreme (LMAS) vs current practice during OHCA. Methods: We conducted a cluster-randomized trial in a single ambulance service in England, with individual paramedics as the unit of randomization. Consenting paramedics were randomized to use either the i-gel or the LMAS or usual practice for all patients with non-traumatic adult OHCA, that they attended over a 12-month period. The primary outcome was study feasibility, including paramedic and patient recruitment and protocol adherence. Secondary outcomes included survival to hospital discharge and 90 days. Results: Of the 535 paramedics approached, 184 consented and 171 attended study training. Each paramedic attended between 0 and 11 patients (median 3; interquartile range 2-5). We recruited 615 patients at a constant rate, although the LMAS arm was suspended in the final two months following three adverse incidents. The study protocol was adhered to in 80% of patients. Patient characteristics were similar in the three study arms, and there were no differences in secondary outcomes. Conclusions: We have shown that a prospective trial of alternative airway management strategies in OHCA, cluster randomized by paramedic, is feasible

A Tale of Three Signatures: practical attack of ECDSA with wNAF

One way of attacking ECDSA with wNAF implementation for the scalar multiplication is to perform a side-channel analysis to collect information, then use a lattice based method to recover the secret key. In this paper, we reinvestigate the construction of the lattice used in one of these methods, the Extended Hidden Number Problem (EHNP). We find the secret key with only 3 signatures, thus reaching the theoretical bound given by Fan, Wang and Cheng, whereas best previous methods required at least 4 signatures in practice. Our attack is more efficient than previous attacks, in particular compared to times reported by Fan et al. at CCS 2016 and for most cases, has better probability of success. To obtain such results, we perform a detailed analysis of the parameters used in the attack and introduce a preprocessing method which reduces by a factor up to 7 the overall time to recover the secret key for some parameters. We perform an error resilience analysis which has never been done before in the setup of EHNP. Our construction is still able to find the secret key with a small amount of erroneous traces, up to 2% of false digits, and 4% with a specific type of error. We also investigate Coppersmith's methods as a potential alternative to EHNP and explain why, to the best of our knowledge, EHNP goes beyond the limitations of Coppersmith's methods

A comparison of vas occlusion techniques: cautery more effective than ligation and excision with fascial interposition

BACKGROUND: Vasectomy techniques have been the subject of relatively few rigorous studies. The objective of this analysis was to compare the effectiveness of two techniques for vas occlusion: intraluminal cautery versus ligation and excision with fascial interposition. More specifically, we aimed to compare early failure rates, sperm concentrations, and time to success between the two techniques. METHODS: We compared semen analysis data from men following vasectomy using two occlusion techniques. Data on intraluminal cautery came from a prospective observational study conducted at four sites. Data on ligation and excision with fascial interposition came from a multicenter randomized controlled trial that evaluated the efficacy of ligation and excision with versus without fascial interposition. The surgical techniques used in the fascial interposition study were standardized. The surgeons in the cautery study used their customary techniques, which varied among sites in terms of type of cautery, use of fascial interposition, excision of a short segment of the vas, and use of an open-ended technique. Men in both studies had semen analyses two weeks after vasectomy and then approximately every four weeks. The two outcome measures for the analyses presented here are (a) time to success, defined as severe oligozoospermia, or <100,000 sperm/mL in two consecutive semen analyses; and (b) early vasectomy failure, defined as >10 million sperm/mL at week 12 or later. RESULTS: Vasectomy with cautery was associated with a significantly more rapid progression to severe oligozoospermia and with significantly fewer early failures (1% versus 5%). CONCLUSION: The use of cautery improves vasectomy outcomes. Limitations of this comparison include (a) the variety of surgical techniques in the cautery study and differences in methods of fascial interposition between the two studies, (b) the uncertain correlation between sperm concentrations after vasectomy and the risk of pregnancy, and (c) the use of historical controls and different study sites

Airway management during in-hospital cardiac arrest in adults: UK national survey and interview study with anaesthetic and intensive care trainees

Background: The optimal airway management strategy for in-hospital cardiac arrest is unknown. Methods: An online survey and telephone interviews with anaesthetic and intensive care trainee doctors identified by the United Kingdom Research and Audit Federation of Trainees. Questions explored in-hospital cardiac arrest frequency, grade and specialty of those attending, proportion of patients receiving advanced airway management, airway strategies immediately available, and views on a randomised trial of airway management strategies during in-hospital cardiac arrest. Results: Completed surveys were received from 128 hospital sites (76% response rate). Adult in-hospital cardiac arrests were attended by anaesthesia staff at 40 sites (31%), intensive care staff at 37 sites (29%) and a combination of specialties at 51 sites (40%). The majority (123/128, 96%) of respondents reported immediate access to both tracheal intubation and supraglottic airways. A bag-mask technique was used ‘very frequently’ or ‘frequently’ during in-hospital cardiac arrest by 111/128 (87%) of respondents, followed by supraglottic airways (101/128, 79%) and tracheal intubation (69/128, 54%). The majority (60/100, 60%) of respondents estimated that ≤30% of in-hospital cardiac arrest patients undergo tracheal intubation, while 34 (34%) estimated this to be between 31% and 70%. Most respondents (102/128, 80%) would be ‘likely’ or ‘very likely’ to recruit future patients to a trial of alternative airway management strategies during in-hospital cardiac arrest. Interview data identified several barriers and facilitators to conducting research on airway management in in-hospital cardiac arrest. Conclusions: There is variation in airway management strategies for adult in-hospital cardiac arrest across the UK. Most respondents would be willing to take part in a randomised trial of airway management during in-hospital cardiac arrest

The Positive Relationship between Moderate-to-Vigorous Physical Activity and Bone Mineral Content Is Not Mediated by Free Leptin Index in Prepubertal Children: The PANIC Study

This is the final version. Available from MDPI via the DOI in this record. The datasets analyzed during the current study are available from the corresponding author on reasonable request.Purpose: Moderate-to-vigorous physical activity (MVPA) positively influences bone mineral content (BMC) in prepubertal children, but it is unknown whether this relationship is partially mediated by free leptin index. The aim of this study was to examine whether the relationship between MVPA and total body less head (TBLH) BMC is mediated or moderated by free leptin index in prepubertal children. Methods: We performed a cross-sectional analysis on 401 children (194 girls) from baseline examinations of the Physical Activity and Nutrition in Childhood Study. We applied the four-way decomposition mediation analysis method to assess whether free leptin index, measured from fasted blood samples, mediated the relationship between accelerometer-measured MVPA and TBLH BMC measured by dual-energy X-ray absorptiometry. Results: MVPA had a positive controlled direct effect on TBLH BMC in girls and boys (β = 0.010 to 0.011, p 0.05). Conclusion: Our study indicates that MVPA positively influences TBLH BMC through pathways not related to free leptin index in predominantly normal-weight prepubertal children, likely primarily through mechanical loading. The relationships between MVPA, free leptin index and TBLH BMC may be influenced by other factors such as pubertal status and adiposity, so it is unknown whether these observations extend to overweight and obese children at different stages of puberty.Medical Research Council (MRC)NIHR Cambridge Biomedical Research CentreSão Paulo Research Foundation-FAPESPSão Paulo Research Foundation-FAPESPKuopio University HospitalMinistry of Education and Culture of FinlandFinnish Innovation Fund SitraSocial Insurance Institution of FinlandFinnish Cultural FoundationJuho Vainio FoundationFoundation for Paediatric ResearchDoctoral Programs in Public HealthPaavo Nurmi FoundationPaulo FoundationDiabetes Research FoundationThe Finnish Medical Society DuodecimOrion Research Foundation srResearch Committee of the Kuopio University Hospital Catchment AreaMinistry of Social Affairs and Health of FinlandThe city of Kuopi