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: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for a biometric authentication system. In one aspect, a method includes broadcasting, through a transceiver, a signal that includes a kiosk identifier; receiving, from a server system, a reference image of the user based on a mobile computing device associated with the user having received the signal and providing the kiosk identifier to the server system; capturing, with a camera, an image of the user; and authenticating the user based on a comparison of the captured image of the user to the reference image of the user based on a comparison of the captured image of the user to the reference image of the user.

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: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium for red eye detection are provided. In one aspect, a system includes an image acquisition device, first and second illuminators, and at least one processor. The first illuminator is arranged closer to the image acquisition device than the second illuminator. The image acquisition device is configured to capture a first facial image of a face of a subject with the first illuminator being on and the second illuminator being off and a second facial image of the face of the subject with the second illuminator being on and the first illuminator being off. The processor can process the first facial image based on the second facial image to determine whether at least one eye of the subject is live by determining that the first facial image includes a red eye reflection from the at least one eye.

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: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for authenticating a user based on passive affective and knowledge-based authentication (AKBA). In one aspect, a method includes data associated with eye movements and ocular dynamics of the user are captured with a camera as the user looks at a graphical user interface (GUI) of a device; an AKBA signature of the user is determined based on the captured data; the user is authenticated based on a comparison of the AKBA signature with an AKBA template associated with the user; and an access to a subset of functions of an application is granted.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining the identity of a user. In one aspect, a method comprises: obtaining at least one image depicting a reflection of light from a lens that is included in a set of eyeglasses; determining, based on the reflection of light from the lens, a set of features characterizing the lens; and determining an identity of a corresponding user based at least in part on the set of features characterizing the lens.

Abstract: Techniques are described for authentication using sound-based monitor detection. In some implementations, the sound (e.g., ultrasound) generated by a monitor is used to detect its presence in the vicinity of a (e.g., portable) computing device that is being used to capture image(s) to be provided to an image-based authentication system. While the computing device is being used to capture image(s) to be provided to the image-based authentication system, the sound data in proximity to the computing device can be captured and analyzed (e.g., using machine learning or other techniques) to determine whether the sound data exhibits a particular pattern and/or characteristics (e.g., signature) that indicates the presence of a monitor in proximity to the computing device. The presence (or absence) of a monitor can be used in determining whether to authenticate the user.

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: 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: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for a biometric authentication system. In one aspect, a method includes broadcasting, through a transceiver, a signal that includes a kiosk identifier; receiving, from a server system, a reference image of the user based on a mobile computing device associated with the user having received the signal and providing the kiosk identifier to the server system; capturing, with a camera, an image of the user; and authenticating the user based on a comparison of the captured image of the user to the reference image of the user based on a comparison of the captured image of the user to the reference image of the user.

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, a vibrating component of a mobile device is vibrated; a vibration signal of the mobile device is detected as a user grips the mobile device; a dynamic grip signature is determined for the user based on the detected vibration signal; and the user is authenticated based on a comparison of the dynamic grip signature to an initial grip template.

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: This document described a method that includes illuminating a first subject with electromagnetic radiation in a first wavelength range, and capturing a first image of the first subject under illumination of the first wavelength range. The method also includes illuminating the first subject with electromagnetic radiation in a second wavelength range, wherein a difference between (i) absorption of the second wavelength range by live human tissue, and (ii) absorption of the first wavelength range by live human tissue satisfies a threshold condition. The method further includes capturing a second image of the first subject under illumination of the second wavelength range, identifying, based on a difference between the first image and the second image, the first subject as an alternative representation of a live person, and preventing access to the secure system responsive to identifying the first subject as an alternative representation of a live person.

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: Computer-implemented methods and systems for image security in computer vision applications are described. A shared secret is stored at an image sensor module and a trusted element. The shared secret includes a device-specific secret value and a definition of a plurality of pixel locations. An image is received at the image sensor module, which generates a watermark based on the secret value and applies the watermark to the image, based on the pixel locations, to create a watermarked image. The watermarked image is received at the trusted element, which validates the watermarked image based on the watermark.

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: Computer-implemented methods and systems for image security in computer vision applications are described. A shared secret is stored at an image sensor module and a trusted element. The shared secret includes a device-specific secret value and a definition of a plurality of pixel locations. An image is received at the image sensor module, which generates a watermark based on the secret value and applies the watermark to the image, based on the pixel locations, to create a watermarked image. The watermarked image is received at the trusted element, which validates the watermarked image based on the watermark.

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, a vibrating component of a mobile device is vibrated; a vibration signal of the mobile device is detected as a user grips the mobile device; a dynamic grip signature is determined for the user based on the detected vibration signal; and the user is authenticated based on a comparison of the dynamic grip signature to an initial grip template.

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.