110 research outputs found

    End-to-end 3D face reconstruction with deep neural networks

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    Monocular 3D facial shape reconstruction from a single 2D facial image has been an active research area due to its wide applications. Inspired by the success of deep neural networks (DNN), we propose a DNN-based approach for End-to-End 3D FAce Reconstruction (UH-E2FAR) from a single 2D image. Different from recent works that reconstruct and refine the 3D face in an iterative manner using both an RGB image and an initial 3D facial shape rendering, our DNN model is end-to-end, and thus the complicated 3D rendering process can be avoided. Moreover, we integrate in the DNN architecture two components, namely a multi-task loss function and a fusion convolutional neural network (CNN) to improve facial expression reconstruction. With the multi-task loss function, 3D face reconstruction is divided into neutral 3D facial shape reconstruction and expressive 3D facial shape reconstruction. The neutral 3D facial shape is class-specific. Therefore, higher layer features are useful. In comparison, the expressive 3D facial shape favors lower or intermediate layer features. With the fusion-CNN, features from different intermediate layers are fused and transformed for predicting the 3D expressive facial shape. Through extensive experiments, we demonstrate the superiority of our end-to-end framework in improving the accuracy of 3D face reconstruction.Comment: Accepted to CVPR1

    VoipLoc : VoIP call provenance using acoustic side-channels

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    We develop a novel technique to determine call provenance in anonymous VoIP communications using acoustic side-channels. The technique exploits location-attributable information embedded within audio speech data. The victim’s speech is exploited as an excitation signal, which is modulated (acted upon) by the acoustic reflection characteristics of the victim’s location. We show that leading VoIP communication channels faithfully transfer this information between sender-receiver pairs, enabling passive receivers to extract a location fingerprint, to establish call provenance. To establish provenance, a fingerprint is compared against a database of labelled fingerprints to identify a match. The technique is fully passive and does not depend on any characteristic background sounds, is speaker independent, and is robust to lossy network conditions. Evaluation using a corpus of recordings of VoIP conversations, over the Tor network, confirms that recording locations can be fingerprinted and detected remotely with low false-positive rate

    Privacy with surgical robotics : challenges in applying contextual privacy theory

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    The use of connected surgical robotics to automate medical procedures presents new privacy challenges. We argue that conventional patient consent protocols no longer work. Indeed robots that replace human surgeons take on an extraordinary level of responsibility. Surgeons undergo years of training and peer review in a strongly regulated environment, and derive trust via a patient's faith in the hospital system. Robots on the other hand derive trust differently, via the integrity of the software that governs their operation. From a privacy perspective, there are two fundamental shifts. First, the threat model has shifted from one where the humans involved were untrusted to one where the robotic software is untrusted. Second, the basic unit of privacy control is no longer a medical record, but is replaced by four new basic units: the subject on which the robot is taking action; the tools used by the robot; the sensors (i.e data) the robot can access; and, finally access to monitoring and calibration services which afford correct operation of the robot. We suggest that contextual privacy provides useful theoretical tools to solve the privacy problems posed by surgical robots. However, it also poses some challenges: not least that the complexity of the contextual-privacy policies, if rigorously specified to achieve verification and enforceability, will be exceedingly high to directly expose to humans that review contextual privacy policies. A medical robot works with both information and physical material. While informational norms allow for judgements about contextual integrity and the transmission principle governs the constraints applied on information transfer, nothing is said about material property. Certainly, contextual privacy provides an anchor for useful notions of privacy in this scenario and thus should be considered to be extended to cover both information and material flows

    A game-theoretic analysis of DoS attacks on driverless vehicles

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    Driverless vehicles are expected to form the foundation of future connected transport infrastructure. A key weakness of connected vehicles is their vulnerability to physical-proximity attacks such as sensor saturation attacks. It is natural to study whether such attacks can be used to disrupt swarms of autonomous vehicles used as part of a large fleet providing taxi and courier delivery services. In this paper, we start to examine the strategic options available to attackers and defenders (autonomous-fleet operators) in such conflicts. We find that attackers have the upper hand in most cases and are able to carry out crippling denial-of-service attacks on fleets, by leveraging the inherent deficiencies of road networks identified by techniques from graph analysis. Experimental results on ten cities using real-world courier traces shows that most cities will require upgraded infrastructure to defend driverless vehicles against denial-of-service attacks. We found several hidden costs that impact equipment designers and operators of driverless vehicles - not least, that road-networks need to be redesigned for robustness against attacks thus raising some fundamental questions about the benefits

    Poster : Unified access control for surgical robotics

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    Ensuring the accuracy of output of surgical robotics is vital, as an incision (during surgery) that is too deep could result in the death of the patient. A large contribution to the level of accuracy of components comes from its calibration. Calibration ensures the output is of high accuracy and is traceable to antecedent calibration units up to national standards. However, each of the levels in the calibration hierarchy have different security requirements (confidentiality and integrity), who may also be in conflict with each other. We propose a hybrid access control model for surgical robotics that maintains integrity and confidentiality requirements across a lattice structure and manages conflicts of interests

    An access control model for robot calibration

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    High assurance surgical robotic systems require robustness to both safety issues and security issues (i.e adversarial interference). In this work, we argue that safety and security are not disjoint properties, but that security is a safety requirement. Surgical robotics presents new information flow requirements that includes multiple levels of confidentiality and integrity, as well as the need for compartmentation arising from conflicts of interest. We develop an information flow model that derives from lattice-based access control. This model addresses the flow constraints of the calibration lifecycle of surgical robots - an important aspect of a high-assurance environment
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