1,648 research outputs found
A Peered Bulletin Board for Robust Use in Verifiable Voting Systems
The Web Bulletin Board (WBB) is a key component of verifiable election
systems. It is used in the context of election verification to publish evidence
of voting and tallying that voters and officials can check, and where
challenges can be launched in the event of malfeasance. In practice, the
election authority has responsibility for implementing the web bulletin board
correctly and reliably, and will wish to ensure that it behaves correctly even
in the presence of failures and attacks. To ensure robustness, an
implementation will typically use a number of peers to be able to provide a
correct service even when some peers go down or behave dishonestly. In this
paper we propose a new protocol to implement such a Web Bulletin Board,
motivated by the needs of the vVote verifiable voting system. Using a
distributed algorithm increases the complexity of the protocol and requires
careful reasoning in order to establish correctness. Here we use the Event-B
modelling and refinement approach to establish correctness of the peered design
against an idealised specification of the bulletin board behaviour. In
particular we show that for n peers, a threshold of t > 2n/3 peers behaving
correctly is sufficient to ensure correct behaviour of the bulletin board
distributed design. The algorithm also behaves correctly even if honest or
dishonest peers temporarily drop out of the protocol and then return. The
verification approach also establishes that the protocols used within the
bulletin board do not interfere with each other. This is the first time a
peered web bulletin board suite of protocols has been formally verified.Comment: 49 page
Autonomous Fault Detection in Self-Healing Systems using Restricted Boltzmann Machines
Autonomously detecting and recovering from faults is one approach for
reducing the operational complexity and costs associated with managing
computing environments. We present a novel methodology for autonomously
generating investigation leads that help identify systems faults, and extends
our previous work in this area by leveraging Restricted Boltzmann Machines
(RBMs) and contrastive divergence learning to analyse changes in historical
feature data. This allows us to heuristically identify the root cause of a
fault, and demonstrate an improvement to the state of the art by showing
feature data can be predicted heuristically beyond a single instance to include
entire sequences of information.Comment: Published and presented in the 11th IEEE International Conference and
Workshops on Engineering of Autonomic and Autonomous Systems (EASe 2014
Secure and Verifiable Electronic Voting in Practice: the use of vVote in the Victorian State Election
The November 2014 Australian State of Victoria election was the first
statutory political election worldwide at State level which deployed an
end-to-end verifiable electronic voting system in polling places. This was the
first time blind voters have been able to cast a fully secret ballot in a
verifiable way, and the first time a verifiable voting system has been used to
collect remote votes in a political election. The code is open source, and the
output from the election is verifiable. The system took 1121 votes from these
particular groups, an increase on 2010 and with fewer polling places
Mechanism for Balancing of GPU Usage Between AI Queue Depth and Graphical Fidelity
Concurrent application demands that exceed available GPU resources can degrade performance and worsen the user experience. However, there are no easy mechanisms for lay users to tailor application performance and control GPU resource allocation. This disclosure describes techniques that enable users to specify preferences for prioritizing computational tasks performed via a GPU via conventional user interface mechanisms. Scheduling and switching workloads and batches of the requested computations on the GPU is performed according to user-specified preferences. Users can leverage the preference settings for managing performance tradeoffs between application functionality, balancing resource allocation when multitasking, troubleshooting potential GPU-related problems, etc. The techniques can enable users to save time and effort in troubleshooting GPU-related problems and can save manufacturers the cost of handling return and replacement of defective hardware
Dynamic Real-time Verification of Program Call Flows
This disclosure describes a dynamic overlay that delineates control flows of an application to identify unexpected code execution pathways that may be indicative of a security breach. Identifying such unexpected (or unauthorized) execution pathways can enable their prevention. The overlay is generated by observing the control flow through the application to produce a histogram of probabilities from a first function call to subsequent function calls. Using the overlay enables the detection of attacks with higher fidelity and at a lower cost than existing approaches
Authenticated Attribution of Media Content Bound to Devices
This disclosure describes techniques to authenticate that a media content item such as a photograph, a video, etc. is attributed to and originated by a particular user, based on the device on which the content was created. The content item is created on a device and associated with a digital signature using an attestation mechanism of the device such as trusted hardware or a sensor pattern that is unique to the device. The digital signature and content item are provided to a register or service for access by other users. When an accessing user views the content item, the content item is verified, via the digital signature, as having originated from the originating user’s device. The accessing user’s device displays the status of user attribution of the content item, indicating that the content item originates from a legitimate user and has not been forged, modified, or stolen. Described techniques are privacy-preserving and do not disclose the identity of the originating user
Using Technology to Enhance Rural Resilience in Pre-hospital Emergencies
The research presented in this paper is supported by RCUK dot.rural Digital Economy Research Hub, University of Aberdeen [grant number EP/G066051/1].Peer reviewedPublisher PD
Response of idealized Hadley circulations to seasonally varying heating
[1] The response of Hadley circulations to displacements of the latitude of maximum heating is investigated in idealized axisymmetric and eddy-permitting models. Consistent with an earlier study and with theory for the nearly inviscid limit (Lindzen and Hou, 1988), the strength of the Hadley circulation is sensitive to displacements of heating: the winter cell strengthens and summer cell weakens when the maximum heating is displaced off the equator. However, in conflict with the nearly inviscid limit but consistent with observations of Earth's atmosphere, the strength of an annually averaged Hadley circulation is comparable to the Hadley circulation driven by an annually averaged heating. The disagreement between these results and the nearly inviscid limit is ascribed to vertical diffusion of momentum and dry static energy in the axisymmetric model and to baroclinic eddy fluxes in the eddy-permitting model. Nonlinear amplification of the annually averaged Hadley circulation is only seen near the upper boundary in simulations with a rigid lid near the tropopause, suggesting that the amplification is an artifact of the upper boundary condition
‘Grounding a PIE in the sky’:Laying empirical foundations for a psychologically informed environment (PIE) to enhance well-being and practice in a homeless organisation
While psychologically informed environments (PIEs) are gaining in prominence in efforts to improve well-being and practice in the homeless sector, their empirical foundations remain tenuous. We present a unique scoping needs analysis of staff and client well-being, staff attitudes and the social–therapeutic climate in a UK-based homeless prevention organisation (prior to PIE implementation). Our aims were: (a) to apply a robust framework to pinpoint need and target forthcoming PIE initiatives and (b) to establish a validated needs baseline that informs and measures efficacy of PIE for its future development. Four established personal and practice well-being measures were administered to 134 (predominantly ‘frontline’) staff and 50 clients. Staff completed the: Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS), Professional Quality of Life Scale (measuring compassion satisfaction [CS], burnout [BO] and secondary traumatic stress [STS]), Attitudes related to Trauma-informed Care Scale (ARTIC-10; measuring practice attitudes towards trauma-informed values) and the Essen Climate Evaluation Schema (EssenCES; measuring perceptions of client cohesion, safety and practitioner relationships in housing projects). Clients completed the WEMWBS and EssenCES. Vulnerability to STS was evident in nearly two-thirds of frontline staff and it was a statistically significant predictor of BO. It was not, however, associated with lesser levels of CS. We discuss this complex dynamic in relation to highlighted strategic recommendations for the PIE framework, and the identified potential challenges in implementing trauma-informed and reflective practice in the organisation. We conclude with a critique of the value and the lessons learnt from our efforts to integrate stronger empirical substance into the PIE approach
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