1,720,971 research outputs found
SHE based Non Interactive Privacy Preserving Biometric Authentication Protocols
Full text linkBeing unique and immutable for each person, biometric signals are widely used in access control systems. While biometric recognition appeases concerns about password's theft or loss, at the same time it raises concerns about individual privacy. Central servers store several enrolled biometrics, hence security against theft must be provided during biometric transmission and against those who have access to the database. If a server's database is compromised, other systems using the same biometric templates could also be compromised as well. One solution is to encrypt the stored templates. Nonetheless, when using traditional cryptosystem, data must be decrypted before executing the protocol, leaving the database vulnerable. To overcame this problem and protect both the server and the client, biometrics should be processed while encrypted. This is possible by using secure two-party computation protocols, mainly based on Garbled Circuits (GC) and additive Homomorphic Encryption (HE). Both GC and HE based solutions are efficient yet interactive, meaning that the client takes part in the computation. Instead in this paper we propose a non-interactive protocol for privacy preserving biometric authentication based on a Somewhat Homomorphic Encryption (SHE) scheme, modified to handle integer values, and also suggest a blinding method to protect the system from spoofing attacks. Although our solution is not as efficient as the ones based on GC or HE, the protocol needs no interaction, moving the computation entirely on the server side and leaving only inputs encryption and outputs decryption to the client
Privacy Protection in Biometric-Based Recognition Systems: A marriage between cryptography and signal processing
No full textSystems employing biometric traits for people authentication and identification are witnessing growing popularity due to the unique and indissoluble link between any individual and his/her biometric characters. For this reason, biometric templates are increasingly used for border monitoring, access control, membership verification, and so on. When employed to replace passwords, biometrics have the added advantage that they do not need to be memorized and are relatively hard to steal. Nonetheless, unlike conventional security mechanisms such as passwords, biometric data are inherent parts of a person?s body and cannot be replaced if they are compromised. Even worse, compromised biometric data can be used to have access to sensitive information and to impersonate the victim for malicious purposes. For the same reason, biometric leakage in a given system can seriously jeopardize the security of other systems based on the same biometrics. A further problem associated with the use of biometric traits is that, due to their uniqueness, the privacy of their owner is put at risk. Geographical position, movements, habits, and even personal beliefs can be tracked by observing when and where the biometric traits of an individual are used to identify him/her
Privacy Protection in Biometric-Based Recognition Systems: a marriage between cryptography and signal processing
No full textSystems employing biometric traits for people authentication and identification are witnessing growing popularity due to the unique and indissoluble link between any individual and his/her biometric characters. For this reason, biometric templates are increasingly used for border monitoring, access control, membership verification, and so on. When employed to replace passwords, biometrics have the added advantage that they do not need to be memorized and are relatively hard to steal. Nonetheless, unlike conventional security mechanisms such as passwords, biometric data are inherent parts of a person?s body and cannot be replaced if they are compromised. Even worse, compromised biometric data can be used to have access to sensitive information and to impersonate the victim for malicious purposes. For the same reason, biometric leakage in a given system can seriously jeopardize the security of other systems based on the same biometrics. A further problem associated with the use of biometric traits is that, due to their uniqueness, the privacy of their owner is put at risk. Geographical position, movements, habits, and even personal beliefs can be tracked by observing when and where the biometric traits of an individual are used to identify him/her
Analysis of the Interactional Aerodynamics of the Vahana eVTOL Using a Medium Fidelity Open Source Tool
No full textThis paper presents the results of a series of aerodynamic simulations of the Vahana demonstrator carried out using a new medium fidelity open source software, called DUST. This tool, developed from the collaboration between Politecnico di Milano and A3 by Airbus LLC, exploits the Object Oriented paradigms of the latest Fortran standards to obtain a coherent formulation of the aerodynamic problem governing the flow field around one or more arbitrary bodies. Such formulation enables DUST to be used for comprehensive aerodynamic analysis on any vehicle configuration, including conventional airplanes, helicopters and new eVTOLs, flying in any flight condition. A series of test cases of increasing complexity are analyzed in the paper to assess the accuracy and the limits of such a new medium fidelity numerical software. Test cases range from the simple Vahana 3-bladed isolated fan in hover to the full vehicle flying at different attitudes. Aerodynamic simulations carried out using DUST are compared and validated against both experimental measurements and high-fidelity numerical simulations to assess the validity of the approach and the limits of the new solver in simulating the most challenging flight conditions for an eVTOL. The model of Vahana is developed using doublet-source singularity panels to represent the fuselage, the canard and the wing, while lifting lines with tabulated aerodynamic characteristics of airfoils are used to capture the compressibility and viscosity effects of the rotating blades of the fans
Semba: Secure multi-biometric authentication
Full text linkBiometrics security is a dynamic research area spurred by the need to protect personal traits from threats like theft, non-authorised distribution, reuse and so on. A widely investigated solution to such threats consists of processing the biometric signals under encryption, in order to avoid any leakage of information towards non-authorised parties. In this study, the authors propose to leverage on the superior performance of multimodal biometric recognition to improve the efficiency of a biometric-based authentication protocol operating on encrypted data under the malicious security model. In the proposed protocol, authentication relies on both facial and iris biometrics, whose representation accuracy is specifically tailored to the trade-off between recognition accuracy and efficiency. From a cryptographic point of view, the protocol relies on Damgård et al. SPDZ. Experimental results show that the multimodal protocol is faster than corresponding unimodal protocols achieving the same accuracy
Mid-Fidelity Analysis of Unsteady Interactional Aerodynamics of Complex VTOL Configurations
Full text linkExperimental Investigation of Vortex Ring State Conditions for Archer Maker eVTOL Tilter Propeller
No full textThis study experimentally explores the behavior of an isolated propeller of an electric vertical takeoff and landing (eVTOL) aircraft, a next-generation type of vehicle that combines the operational capabilities of both helicopters and airplanes, in vortex ring state (VRS). VRS is a hazardous aerodynamic phenomenon that occurs when a propeller in vertical descent interacts with its own wake, forming a vortex ring around the propeller disk. Depending on the inflow and operating conditions of the propeller, VRS can lead to a significant loss of thrust, making it a critical flight condition for helicopters, tiltrotors, and eVTOL aircraft. Despite its importance, VRS has not yet been extensively studied in the context of eVTOL systems. This research study, carried out under the collaboration between Archer Aviation and the Department of Aerospace Science and Technology of Politecnico di Milano, focuses on characterizing the performance of a propeller of an eVTOL vehicle during vertical descent and analysing the flow field around the propeller blades in VRS. Experimental tests were conducted at the”S. De Ponte” wind tunnel of Politecnico di Milano using a 1:4 scaled model of one of the tilting propellers of Archer Aviation eVTOL Maker vehicle
Infrared Thermography Measurements over an eVTOL Full-Scale Wing Section Equipped with Propellers Mounted on a Boom
No full textThe present paper describes the results of an experimental wind tunnel test campaign aimed at investigating and characterizing the complicated aerodynamic flow patterns around a wing section equipped with propellers mounted on a boom. The investigated configuration is meant to be representative of a full-scale eVTOL aircraft in cruise flight condition. The Infrared Thermography technique enabled a quantitative evaluation of the amount of laminar flow for the baseline airfoil section and also for the wing airfoil under the influence of the propeller at different thrust conditions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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