Abstract: The technology described in this document can be embodied in a method for identifying a user of secured system. The method includes transmitting, using a first transceiver in an array of multiple transceivers, a first electromagnetic signal in the microwave range. An electromagnetic signal representing a first response of a portion of a subject to the first electromagnetic signal is received, by at least one transceiver of the array of multiple transceivers. The subject is identified based at least in part on one or more parameters of the first response.

Abstract: A method includes receiving a first sequence of images of a first subject captured over a time period in which relative locations of the image acquisition device with respect to the first subject varies. A first image and a second image are selected as representing a first and second relative locations, respectively, of the image acquisition device with respect to the first subject. A first set of points and a second set of points are generated in a three-dimensional space, using the first image and the second image as a stereo pair, the first and second sets of points representing the first subject, and a background, respectively. It is determined that a difference between a first depth associated with the first set of points, and a second depth associated with the second set of points satisfies a threshold condition, and in response, access to a secure system is prevented.

Abstract: The technology described in this document can be embodied in a method for verifying an authenticated state of a device. In one aspect, the method includes capturing, during a primary authentication process, first auxiliary user identifying information for short-term authentication verification of the subject. The first auxiliary user identifying information includes first eyebrow biometric information for the subject and first eyeglass frame information for the subject. A short-term authentication verification process is performed to verify identify of the subject. In response to determining that a match score that indicates a degree of match between the first auxiliary user identifying information and captured second auxiliary user identifying information meets or exceeds a predetermined threshold, an authenticated state for the subject is verified. In response to determining that the match score does not meet or exceed the predetermined threshold, the authenticated state for the subject is ended.

Abstract: A method for generating a composite image includes receiving a first image that includes an eyeglass lens illuminated by a first illumination source radiating electromagnetic radiation in a first polarization state, and receiving a second image that includes the eyeglass lens illuminated by a second illumination source radiating electromagnetic radiation in a second polarization state. The second polarization state is different from the first polarization state, and the second illumination source is spatially separated from the first illumination source. The method also includes identifying, in the first image, a first portion that represents a reflection of the first illumination source on the eyeglass lens, and generating the composite image in which the first portion is replaced by a corresponding second portion from the second image. The first portion and the second portion represent substantially a same portion of the eyeglass lens.

Abstract: The technology described in this document can be embodied in a computer-implemented method that includes receiving, at one or more servers from a first computing device, (i) first identification information identifying the first computing device or an application executing on the first computing device, and (ii) second identification information identifying a second computing device. The second identification information is obtained by the first computing device by detecting changes to one or more parameters of a magnetic field generated by the second computing device. The method also includes determining, by the server based on the first information, identity information of a user associated with the first computing device, and transmitting, from the one or more servers to the second computing device, the identity information, such that the identity information is usable by the second computing device to verify an access attempt by the user.

Abstract: The technology described in this document can be embodied in a computer-implemented method that includes receiving, at one or more servers from a first computing device, (i) first identification information identifying the first computing device or an application executing on the first computing device, and (ii) second identification information identifying a second computing device. The second identification information is obtained by the first computing device by detecting changes to one or more parameters of a magnetic field generated by the second computing device. The method also includes determining, by the server based on the first information, identity information of a user associated with the first computing device, and transmitting, from the one or more servers to the second computing device, the identity information, such that the identity information is usable by the second computing device to verify an access attempt by the user.

Abstract: The technology described in this document can be embodied in a method that includes receiving, at one or more servers from a first computing device, (i) authentication information identifying a user-account associated with (a) the first computing device or (b) an application executing on the first computing device, and (ii) a transaction identifier generated by a second computing device. The transaction identifier is obtained by the first computing device by detecting one or more parameters of a magnetic field generated by the second computing device. The method also includes determining, by the one or more servers, that the user-account is authorized to initiate a transaction identified by the transaction identifier, and in response to determining that the user-account is authorized to initiate the transaction, transmitting, from the one or more servers to the second computing device, confirmation information usable by the second computing device to proceed with the transaction.

Abstract: The technology described in this document can be embodied in a method that includes receiving, at one or more servers from a first computing device, (i) authentication information identifying a user-account associated with (a) the first computing device or (b) an application executing on the first computing device, and (ii) a transaction identifier generated by a second computing device. The transaction identifier is obtained by the first computing device by detecting one or more parameters of a magnetic field generated by the second computing device. The method also includes determining, by the one or more servers, that the user-account is authorized to initiate a transaction identified by the transaction identifier, and in response to determining that the user-account is authorized to initiate the transaction, transmitting, from the one or more servers to the second computing device, confirmation information usable by the second computing device to proceed with the transaction.

Abstract: A method includes receiving a first image and a second image, wherein the first and second images represent first and second relative locations, respectively, of an image acquisition device with respect to a subject. The method also includes determining, using the first and second images, a total relative displacement of the subject with respect to the image acquisition device between a time of capture of the first image and a time of capture of the second image, and determining, based on sensor data associated with one or more sensors associated with the image acquisition device, a component of the total relative displacement associated with a motion of the image acquisition device. The method also includes determining, based on a difference between the first total relative displacement and the component, that the first subject is an alternative representation of a live person, and in response, preventing access to a secure system.

Abstract: A method for generating a composite image includes receiving a first image that includes an eyeglass lens illuminated by a first illumination source radiating electromagnetic radiation in a first polarization state, and receiving a second image that includes the eyeglass lens illuminated by a second illumination source radiating electromagnetic radiation in a second polarization state. The second polarization state is different from the first polarization state, and the second illumination source is spatially separated from the first illumination source. The method also includes identifying, in the first image, a first portion that represents a reflection of the first illumination source on the eyeglass lens, and generating the composite image in which the first portion is replaced by a corresponding second portion from the second image. The first portion and the second portion represent substantially a same portion of the eyeglass lens.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for a biometric authentication system. In one aspect, a method includes capturing pressure measurement data as a sequence of pressure maps as the user applies pressure to the pressure sensing device; determining a dynamic pressure signature for the user based on the pressure measurement data, the dynamic pressure signature including a temporal sequence of the pressure maps; and authenticating the user based on a comparison of the dynamic pressure signature to an initial dynamic pressure signature.

Abstract: The technology described in this document can be embodied in a method for generating an iris identifier. The method includes obtaining a plurality of images of an iris, and generating a binary code for each of the plurality of images of the iris, the binary code including a sequence of bits. The method also includes identifying a first pattern of bits for which bit values and bit-locations are the same across a plurality of the binary codes, generating a first index based on the first pattern of bits, and then storing the first index on a storage device in accordance with a database management system. The first index is linked to biometric information of a different modality for a corresponding user.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for a biometric authentication system having anti-spoofing capabilities. A biometric authentication system can use a vibrating component of a mobile device to determine whether the mobile device is oriented in a self-portrait orientation or in an orientation other than the self-portrait orientation based on a vibration response signal received from sensors on the mobile device. In response to determining that the mobile device is oriented in an orientation other than the self-portrait orientation, the biometric authentication system can prevent access attempts to one or more secure systems.

Abstract: A method for generating a composite image includes receiving a first image that includes an eyeglass lens illuminated by a first illumination source radiating electromagnetic radiation in a first polarization state, and receiving a second image that includes the eyeglass lens illuminated by a second illumination source radiating electromagnetic radiation in a second polarization state. The second polarization state is different from the first polarization state, and the second illumination source is spatially separated from the first illumination source. The method also includes identifying, in the first image, a first portion that represents a reflection of the first illumination source on the eyeglass lens, and generating the composite image in which the first portion is replaced by a corresponding second portion from the second image. The first portion and the second portion represent substantially a same portion of the eyeglass lens.

Abstract: The technology described in this document can be embodied in a method that includes obtaining, by one or more image acquisition devices, a first image of a portion of a human body under illumination by electromagnetic radiation in a first wavelength range, and obtaining a second image of the portion of the human body under illumination by electromagnetic radiation in a second wavelength range. The method also includes generating, by one or more processing devices, a third image or template that combines information from the first image with information from the second image. The method also includes determining that one or more metrics representing a similarity between the third image and a template satisfy a threshold condition, and responsive to determining that the one or more metrics satisfy a threshold condition, providing access to the secure system.

Abstract: Technology described herein includes a method that includes receiving, at one or more processing devices, data corresponding to a first image, and determining, by the one or more processing devices based on the received data, that a first set of pixel values of the first image corresponds to illumination of a first representative wavelength, and at least a second set of pixel values of the first image corresponds to illumination of a second representative wavelength. The illuminations of the first and second representative wavelengths constitute at least a portion of a first illumination sequence pattern used in capturing the first image. The method also includes determining that the first illumination sequence pattern matches a second illumination sequence pattern associated with a device from which the first image is expected to be received, and in response, initiating a biometric authentication process for authenticating a subject represented in the first image.

Abstract: A method for generating a composite image includes receiving a first image that includes an eyeglass lens illuminated by a first illumination source radiating electromagnetic radiation in a first polarization state, and receiving a second image that includes the eyeglass lens illuminated by a second illumination source radiating electromagnetic radiation in a second polarization state. The second polarization state is different from the first polarization state, and the second illumination source is spatially separated from the first illumination source. The method also includes identifying, in the first image, a first portion that represents a reflection of the first illumination source on the eyeglass lens, and generating the composite image in which the first portion is replaced by a corresponding second portion from the second image. The first portion and the second portion represent substantially a same portion of the eyeglass lens.

Abstract: In one aspect, a method includes receiving a sequence of images of a subject, the sequence captured by an image acquisition device over a time period in which relative locations of the image acquisition device varies with respect to the subject. A first image and a second image are selected from the first sequence of images. The first and second images represent a first relative location and a second relative location, respectively, of the image acquisition device with respect to the subject. A three-dimensional representation of the first subject is generated using the first image and the second image as a stereo pair. It is determined, based on the first three dimensional representation, that the first subject is an alternative representation of a live person, and in response, access to a secure system is prevented.

Abstract: Technology described herein includes a method that includes receiving, at one or more processing devices, data corresponding to a first image, and determining, by the one or more processing devices based on the received data, that a first set of pixel values of the first image corresponds to illumination of a first representative wavelength, and at least a second set of pixel values of the first image corresponds to illumination of a second representative wavelength. The illuminations of the first and second representative wavelengths constitute at least a portion of a first illumination sequence pattern used in capturing the first image. The method also includes determining that the first illumination sequence pattern matches a second illumination sequence pattern associated with a device from which the first image is expected to be received, and in response, initiating a biometric authentication process for authenticating a subject represented in the first image.

Abstract: In a feature extraction and pattern matching system, image sharpening can enable vascular point detection (VPD) for detecting points of interest from visible vasculature of the eye. Pattern Histograms of Extended Multi-Radii Local Binary Patterns and/or Pattern Histograms of Extended Multi-Radii Center Symmetric Local Binary Patterns can provide description of portions of images surrounding a point of interest, and enrollment and verification templates can be generated using points detected via VPD and the corresponding descriptors. Inlier point pairs can be selected from the enrollment and verification templates, and a first match score indicating similarity of the two templates can be computed based on the number of inlier point pairs and one or more parameters of a transform selected by the inlier detection. A second match score can be computed by applying the selected transform, and either or both scores can be used to authenticate the user.