Ear Canal Acoustic Authentication Using Dual Frequency Signals
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Solution Overview
Problem
Otoacoustic authentication methods face challenges due to changes in the acoustical features of the ear canal caused by the insertion and removal of earphone/microphone devices, leading to inaccurate authentication and the need for additional authentication means like user IDs, which can be cumbersome, especially in emergency situations.
Innovation Solution
A personal authentication device that uses both audible and inaudible acoustical signals to detect and measure changes in the ear canal, performing initial authentication with an audible signal and secondary authentication with an inaudible signal to ensure accurate identification and prevent spoofing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If otoacoustic authentication is performed using a single audible acoustical signal, then the authentication process is simple and quick, but the authentication accuracy is insufficient and vulnerable to spoofing
Solution Approach 1:
The authentication process is segmented into multiple stages: first authentication using an audible acoustical signal for quick verification, and second authentication using an inaudible acoustical signal for high-accuracy verification. This segmentation allows the system to balance speed and accuracy by performing different types of authentication at different stages.
Solution Approach 2:
The system performs excessive authentication by using both audible and inaudible signals beyond what a single signal would provide. This partial or excessive action ensures that even if one authentication method is compromised, the other provides additional security layers.
2Ease of operation
If only audible acoustical signals are used for authentication, then the user experience is comfortable, but the authentication is vulnerable to spoofing attacks
Solution Approach 1:
The inaudible acoustical signal acts as an intermediary verification layer that does not directly interact with the user's auditory system, thereby maintaining user comfort while providing an additional security mechanism that is difficult to spoof.
Solution Approach 2:
The system changes the frequency parameter of the acoustical signal by using inaudible frequencies for the second authentication stage. This parameter change enables the system to detect ear canal characteristics that are difficult to replicate, thereby preventing spoofing while maintaining user comfort during the initial audible authentication.
3Reliability
If additional authentication means such as user ID input are required, then authentication accuracy is improved, but the authentication process becomes time-consuming and cumbersome
Solution Approach 1:
The system replaces the mechanical interaction of user ID input (typing, mouse operation) with an acoustic-based authentication method using inaudible signals. This substitution eliminates the need for external input devices and reduces authentication time while maintaining or improving accuracy.
Solution Approach 2:
The ear canal itself serves as the authentication medium for the second authentication stage. The system utilizes the natural acoustic properties of the user's own ear canal to perform verification, eliminating the need for external authentication means and reducing the time required for accurate authentication.
4Ease of operation
If the earphone/microphone device is re-inserted due to discomfort, then user comfort is maintained, but the acoustical feature changes making accurate authentication difficult
Solution Approach 1:
The system performs preliminary authentication using the audible signal before the user may feel discomfort and re-insert the device. This preliminary action captures the acoustical features at the initial correct position, and the subsequent inaudible signal authentication ensures accuracy even if minor position changes occur during re-insertion.
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
Enables quick and accurate authentication with reduced user burden, minimizing the impact of device positioning errors and environmental factors, while preventing unauthorized access.
Implementation Method 1
an acoustical signal to be bounced off the ear canal changes
Data Source
AI summary
Provided are a personal authentication device performing accurate authentication immediately follow insertion an earphone/microphone device to wear, and preventing spoofing after authentication. This device: detects contact of an earphone/microphone device with a propagation path constituting part of the head of a person; generates a first acoustical signal in an audible range upon detecting said contact; measures an acoustical signal resulting from propagation of the first acoustical signal; determines that first authentication of the person is successful if the measured propagated first acoustical signal satisfies predetermined conditions; generates a second acoustical signal in an inaudible range higher in frequency than said audible range; measures an acoustical signal resulting from propagation of the second acoustical signal; and performs second authentication in which, if the measured propagated second acoustical signal satisfies predetermined conditions, then it is determined that the person is the person to be authenticated, for whom the first authentication is successful.