Fingerprint Sensor Fraud Detection via Total Reflection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for detecting fraud in fingerprint capture devices are not robust against careful fraud attempts and require incompressible acquisition times, degrading the ergonomics of the sensor.
Innovation Solution
A fraud detection method using the principle of total dark-field reflection, where only light rays originating from diffusion in the finger are captured, allowing for efficient fraud detection by analyzing light intensity and gradient curves to validate the presence of real skin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If image analysis methods are used to detect fraud, then the detection process can be implemented quickly, but the methods are not robust against sophisticated fraud attempts
Solution Approach 1:
The patent replaces complex mechanical/image analysis systems with an optical system based on total reflection principles. The sensor captures light reflected at specific angles from the fingerprint, providing fraud detection through optical properties rather than complex image processing, thus improving reliability while reducing computational complexity
Solution Approach 2:
The invention changes the detection parameter from image-based features to optical reflection intensity and angular distribution. By measuring light reflection at specific angles (total reflection) and comparing it to reference values, the system achieves robust fraud detection through physical parameter changes rather than complex image analysis
2Reliability
If physiological measurement methods are used to validate real skin, then fraud detection robustness is improved, but the acquisition time becomes incompressible and ergonomics are degraded
Solution Approach 1:
The patent replaces time-consuming physiological measurements (perspiration, pulse, oximetry) with instantaneous optical reflection measurements. The total reflection optical system captures fraud detection data in the same brief moment the finger is placed on the sensor, eliminating the need for extended acquisition periods and maintaining excellent ergonomics
Solution Approach 2:
The optical system utilizes the natural optical properties of real skin versus artificial materials. Real skin inherently produces specific total reflection patterns due to its biological structure, allowing the system to self-validate without requiring additional measurement time or external physiological stimuli
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
The method provides robust fraud detection while maintaining acceptable user time, enhancing the security and efficiency of fingerprint authentication processes.
Implementation Method 1
only light rays originating from the finger resulting from scattering within the finger are used
Implementation Method 2
principle of total dark-field reflection, where only light rays originating from diffusion in the finger are captured
Data Source
Figure 1
Figure 2~3
Figure 4A~4B
AI summary
A method for detecting fraud when using a body part fingerprint capture device that employs a total reflection dark-field principle and comprises a transparent slide on which a body part to be verified is placed. The method includes: using said device to acquire (61) a first fingerprint image with illumination of the body part such that the entire surface of the body part in contact with the transparent slide reflects light; using said device to acquire (63) at least a second fingerprint image by illuminating the body part with a single LED; obtaining (67) for each second fingerprint image representative information of a level of light re-emitted by the body part using each image obtained; and comparing (68) each piece of information obtained to reference information to validate that the body part is a genuine body part.