A Cryptographic Analysis of the WireGuard Protocol

WireGuard (Donenfeld, NDSS 2017) is a recently proposed secure network tunnel operating at layer 3. WireGuard aims to replace existing tunnelling solutions like IPsec and OpenVPN, while requiring less code, being more secure, more performant, and easier to use. The cryptographic design of WireGuard is based on the Noise framework. It makes use of a key exchange component which combines long-term and ephemeral Diffie-Hellman values (along with optional preshared keys). This is followed by the use of the established keys in an AEAD construction to encapsulate IP packets in UDP. To date, WireGuard has received no rigorous security analysis. In this paper, we, rectify this. We first observe that, in order to prevent Key Compromise Impersonation (KCI) attacks, any analysis of WireGuard\u27s key exchange component must take into account the first AEAD ciphertext from initiator to responder. This message effectively acts as a key confirmation and makes the key exchange component of WireGuard a 1.5 RTT protocol. However, the fact that this ciphertext is computed using the established session key rules out a proof of session key indistinguishability for WireGuard\u27s key exchange component, limiting the degree of modularity that is achievable when analysing the protocol\u27s security. To overcome this proof barrier, and as an alternative to performing a monolithic analysis of the entire WireGuard protocol, we add an extra message to the protocol. This is done in a minimally invasive way that does not increase the number of round trips needed by the overall WireGuard protocol. This change enables us to prove strong authentication and key indistinguishability properties for the key exchange component of WireGuard under standard cryptographic assumptions

Continuous-mode 448 kHz capacitive resistive monopolar radiofrequency induces greater deep blood flow changes compared to pulsed mode shortwave: a crossover study in healthy adults

This document is the Accepted Manuscript version of the following article: Binoy Kumaran, Anthony Herbland and Tim Watson, ‘Continuous-mode 448 kHz capacitive resistive monopolar radiofrequency induces greater deep blood flow changes compared to pulsed mode shortwave: a crossover study in healthy adults’, European Journal of Physiotheraphy, first published online 20 April 2017. The version of record is available online at doi: http://dx.doi.org/10.1080/21679169.2017.1316310. © 2017 Informa UK Limited, trading as Taylor & Francis Group.Aims: Radiofrequency-based electrophysical agents (EPAs) have been used in therapy practice over several decades (e.g. shortwave therapies). Currently, there is insufficient evidence supporting such EPAs operating below shortwave frequencies. This laboratory-based study investigated the deep physiological effects of 448 kHz capacitive resistive monopolar radiofrequency (CRMRF) and compared them to pulsed shortwave therapy (PSWT). Methods: In a randomized crossover study, 17 healthy volunteers initially received four treatment conditions: high, low and placebo dose conditions receiving 15-min CRMRF treatment and a control condition receiving no intervention. Fifteen participants additionally received high-dose PSWT as fifth condition, for comparison. Pre- and post-treatment measurements of deep blood flow and tissue extensibility were obtained using Doppler ultrasound and sonoelastography. Group data were compared using analysis of variance model. Statistical significance was set at p ≤ .05, 0.8 power, and 95% confidence interval. Results: Significant increases in volume and intensity of deep blood flow were obtained with CRMRF over placebo, control (p = .003) and PSWT (p < .001). No significant changes in blood flow velocity or tissue extensibility were noted for any condition. Conclusions: Deep blood flow changes with CRMRF were more pronounced than that with PSWT, placebo or control. Potential greater therapeutic benefits need to be confirmed with comparative clinical studies.Peer reviewe

The rise of policy coherence for development: a multi-causal approach

In recent years policy coherence for development (PCD) has become a key principle in international development debates, and it is likely to become even more relevant in the discussions on the post-2015 sustainable development goals. This article addresses the rise of PCD on the Western donors’ aid agenda. While the concept already appeared in the work of Organisation for Economic Co-operation and Development (OECD) in the early 1990s, it took until 2007 before PCD became one of the Organisation’s key priorities. We adopt a complexity-sensitive perspective, involving a process-tracing analysis and a multi-causal explanatory framework. We argue that the rise of PCD is not as contingent as it looks. While actors such as the EU, the DAC and OECD Secretariat were the ‘active causes’ of the rise of PCD, it is equally important to look at the underlying ‘constitutive causes’ which enabled policy coherence to thrive well

Variation in pre- and post-copulatory sexual selection on male genital size in two species of lygaeid bug

This study was funded by the Natural Environmental Research Council (DTG studentship 1109354 to LRD).Sexual selection has been shown to be the driving force behind the evolution of the sometimes extreme and elaborate genitalia of many species. Sexual selection may arise before and/or after mating, or vary according to other factors such as the social environment. However, bouts of selection are typically considered in isolation. We measured the strength and pattern of selection acting on the length of the male intromittent organ (or processus) in two closely related species of lygaeid seed bug: Lygaeus equestris and Lygaeus simulans. In both species, we measured both pre- and post-copulatory selection. For L. equestris, we also varied the experimental choice design used in mating trials. We found contrasting pre- and post-copulatory selection on processus length in L. equestris. Furthermore, significant pre-copulatory selection was only seen in mating trials in which two males were present. This selection likely arises indirectly due to selection on a correlated trait, as the processus does not interact with the female prior to copulation. In contrast, we were unable to detect significant pre- or post-copulatory selection on processus length in L. simulans. However, a formal meta-analysis of previous estimates of post-copulatory selection on processus length in L. simulans suggests that there is significant stabilising selection across studies, but the strength of selection varies between experiments. Our results emphasise that the strength and direction of sexual selection on genital traits may be multifaceted and can vary across studies, social contexts and different stages of reproduction.Publisher PDFPeer reviewe

Pre-cooling for endurance exercise performance in the heat: a systematic review.

PMCID: PMC3568721The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1741-7015/10/166. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Endurance exercise capacity diminishes under hot environmental conditions. Time to exhaustion can be increased by lowering body temperature prior to exercise (pre-cooling). This systematic literature review synthesizes the current findings of the effects of pre-cooling on endurance exercise performance, providing guidance for clinical practice and further research

An Electron Fixed Target Experiment to Search for a New Vector Boson A' Decaying to e+e-

We describe an experiment to search for a new vector boson A' with weak coupling alpha' > 6 x 10^{-8} alpha to electrons (alpha=e^2/4pi) in the mass range 65 MeV < m_A' < 550 MeV. New vector bosons with such small couplings arise naturally from a small kinetic mixing of the "dark photon" A' with the photon -- one of the very few ways in which new forces can couple to the Standard Model -- and have received considerable attention as an explanation of various dark matter related anomalies. A' bosons are produced by radiation off an electron beam, and could appear as narrow resonances with small production cross-section in the trident e+e- spectrum. We summarize the experimental approach described in a proposal submitted to Jefferson Laboratory's PAC35, PR-10-009. This experiment, the A' Experiment (APEX), uses the electron beam of the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory (CEBAF) at energies of ~1-4 GeV incident on 0.5-10% radiation length Tungsten wire mesh targets, and measures the resulting e+e- pairs to search for the A' using the High Resolution Spectrometer and the septum magnet in Hall A. With a ~1 month run, APEX will achieve very good sensitivity because the statistics of e+e- pairs will be ~10,000 times larger in the explored mass range than any previous search for the A' boson. These statistics and the excellent mass resolution of the spectrometers allow sensitivity to alpha'/alpha one to three orders of magnitude below current limits, in a region of parameter space of great theoretical and phenomenological interest. Similar experiments could also be performed at other facilities, such as the Mainz Microtron.Comment: 19 pages, 12 figures, 2 table

Haplotype Reconstruction Error as a Classical Misclassification Problem: Introducing Sensitivity and Specificity as Error Measures

BACKGROUND: Statistically reconstructing haplotypes from single nucleotide polymorphism (SNP) genotypes, can lead to falsely classified haplotypes. This can be an issue when interpreting haplotype association results or when selecting subjects with certain haplotypes for subsequent functional studies. It was our aim to quantify haplotype reconstruction error and to provide tools for it. METHODS AND RESULTS: By numerous simulation scenarios, we systematically investigated several error measures, including discrepancy, error rate, and R(2), and introduced the sensitivity and specificity to this context. We exemplified several measures in the KORA study, a large population-based study from Southern Germany. We find that the specificity is slightly reduced only for common haplotypes, while the sensitivity was decreased for some, but not all rare haplotypes. The overall error rate was generally increasing with increasing number of loci, increasing minor allele frequency of SNPs, decreasing correlation between the alleles and increasing ambiguity. CONCLUSIONS: We conclude that, with the analytical approach presented here, haplotype-specific error measures can be computed to gain insight into the haplotype uncertainty. This method provides the information, if a specific risk haplotype can be expected to be reconstructed with rather no or high misclassification and thus on the magnitude of expected bias in association estimates. We also illustrate that sensitivity and specificity separate two dimensions of the haplotype reconstruction error, which completely describe the misclassification matrix and thus provide the prerequisite for methods accounting for misclassification

Suppression of star formation in early-type galaxies by feedback from supermassive black holes

Detailed high-resolution observations of the innermost regions of nearby galaxies have revealed the presence of supermassive black holes1. These black holes may interact with their host galaxies by means of 'feedback' in the form of energy and material jets; this feedback affects the evolution of the host and gives rise to observed relations between the black hole and the host. Here we report observations of the ultraviolet emissions of massive early-type galaxies. We derive an empirical relation for a critical black-hole mass (as a function of velocity dispersion) above which the outflows from these black holes suppress star formation in their hosts by heating and expelling all available cold gas. Supermassive black holes are negligible in mass compared to their hosts but nevertheless seem to play a critical role in the star formation history of galaxies.Comment: Nature, in press. 27 pages, 4 Figures. Article & supplements with high-resolution figures can be downloaded at: http://www-astro.physics.ox.ac.uk/~kevins/PAPERS/AGN_feedback.pd

Impact of Allogeneic Hematopoietic Stem Cell Transplantation on the HIV Reservoir and Immune Response in 3 HIV-Infected Individuals

Background: Allogeneic hematopoietic stem cell transplantation (HSCT) can lead to significant changes to the HIV reservoir and HIV immune responses, indicating that further characterization of HIV-infected patients undergoing HSCT is warranted. Methods: We studied 3 patients who underwent HSCT after either reduced intensity conditioning or myeloablative conditioning regimen. We measured HIV antigens and antibodies (Ag/Ab), HIV-specific CD4 + T-cell responses, HIV RNA, and DNA in plasma, peripheral blood mononuclear cells, isolated CD4 + T cells from peripheral blood, and lymph node cells. The patients remained on antiretroviral therapy throughout the follow-up period. Results: All patients have been in continued remission for 4-6 years post-HSCT. Analyses of HIV RNA and DNA levels showed substantial reductions in HIV reservoir-related measurements in all 3 patients, changes in immune response varied with pronounced reductions in 2 patients and a less dramatic reduction in 1 patient. One patient experienced unexpected viral rebound 4 years after HSCT. Conclusions: These 3 cases highlight the substantial changes to the HIV reservoir and the HIV immune response in patients undergoing allogeneic HSCT. The viral rebound observed in 1 patient indicates that replication competent HIV can re-emerge several years after HSCT despite these marked changes

Generalist care managers for the treatment of depressed medicaid patients in North Carolina: A pilot study

BACKGROUND: In most states, mental illness costs are an increasing share of Medicaid expenditures. Specialized depression care managers (CM) have consistently demonstrated improvements in patient outcomes relative to usual primary care (UC), but are costly and may not be fully utilized in smaller practices. A generalist care manager (GCM) could manage multiple chronic conditions and be more accepted and cost-effective than the specialist depression CM. We designed a pilot program to demonstrate the feasibility of training/deploying GCMs into primary care settings. METHODS: We randomized depressed adult Medicaid patients in 2 primary care practices in Western North Carolina to a GCM intervention or to UC. GCMs, already providing services in diabetes and asthma in both study arms, were further trained to provide depression services including self-management, decision support, use of information systems, and care management. The following data were analyzed: baseline, 3- and 6-month Patient Health Questionnaire (PHQ9) scores; baseline and 6-month Short Form (SF) 12 scores; Medicaid claims data; questionnaire on patients' perceptions of treatment; GCM case notes; physician and office staff time study; and physician and office staff focus group discussions. RESULTS: Forty-five patients were enrolled, the majority with preexisting depression. Both groups improved; the GCM group did not demonstrate better clinical and functional outcomes than the UC group. Patients in the GCM group were more likely to have prescriptions of correct dosing by chart data. GCMs most often addressed comorbid conditions (36%), then social issues (27%) and appointment reminders (14%). GCMs recorded an average of 46 interactions per patient in the GCM arm. Focus group data demonstrated that physicians valued using GCMs. A time study documented that staff required no more time interacting with GCMs, whereas physicians spent an average of 4 minutes more per week. CONCLUSION: GCMs can be trained in care of depression and other chronic illnesses, are acceptable to practices and patients, and result in physicians prescribing guideline concordant care. GCMs appear to be a feasible intervention for community medical practices and to warrant a larger scale trial to test their appropriateness for Medicaid programs nationally