Ultrasonic Interferometry for Face Authentication Anti-Spoofing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Face authentication systems struggle to distinguish between a real human face and presentation attacks, such as images or masks, leading to unauthorized access, and existing methods that rely on liveliness detection can increase latency.
Innovation Solution
A face-authentication system using ultrasound and interferometry-based coherence to evaluate the coherence between reflections from multiple transducers, distinguishing between a real human face and presentation attacks by analyzing differences in ultrasonic energy reflection patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If camera-based face authentication is used, then user convenience is improved, but the system becomes vulnerable to presentation attacks
Solution Approach 1:
The patent introduces ultrasound waves as an intermediary physical phenomenon to detect face properties. The ultrasound interacts with the face tissue and generates acoustic signals that reveal structural characteristics, serving as a mediator between the authentication system and the face being verified.
Solution Approach 2:
The patent replaces the optical camera-based detection system with an acoustic ultrasound-based system. This substitution uses mechanical wave propagation through tissue rather than light reflection, enabling detection of subsurface structural properties that cameras cannot observe.
2Reliability
If traditional liveliness detection methods are used, then authentication security is improved, but detection latency increases
Solution Approach 1:
The patent uses periodic ultrasound wave transmission and reception to continuously probe face properties. The periodic nature of ultrasound waves enables rapid successive measurements without requiring extended capture sequences, reducing latency while maintaining detection reliability.
Solution Approach 2:
The patent changes the detection parameter from optical surface properties (captured by cameras) to acoustic impedance and sound speed properties (measured by ultrasound). This parameter change enables faster detection since ultrasound provides immediate structural information through wave propagation characteristics rather than requiring multiple image captures.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Effectively prevents unauthorized access by accurately differentiating between a human face and presentation attacks, reducing latency and enhancing security without requiring additional capture time.
Implementation Method 1
transmitting an ultrasonic transmit signal and receiving at least two ultrasonic receive signals using at least two transducers of the ultrasonic sensor. The at least two ultrasonic receive signals comprise respective versions of the ultrasonic transmit signal that is reflected by an object
Implementation Method 2
generating an interferogram based on the at least two ultrasonic receive signals. The interferogram comprises coherence information and phase information
Data Source
AI summary
Techniques and apparatuses are described that implement face authentication anti-spoofing using interferometry-based coherence. In particular, a face-authentication system uses ultrasound to distinguish between a real human face and a presentation attack that uses instruments to present a version of a human face. The face-authentication system includes or communicates with an ultrasonic sensor, which can detect a presentation attack and notify the face-authentication system. In general, the ultrasonic sensor uses interferometry to evaluate an amount of coherence (or similarity) between reflections observed by two or more transducers. In this way, the ultrasonic sensor can prevent unauthorized actors from using the presentation attack to gain access to a user's account or information.