Dual-Modulated QR Code Using Elliptical Markers for Secure Credential Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Users face security risks when entering secure website credentials on smartphones or tablets, as remotely located video cameras can capture sensitive information such as passwords, and existing methods require manual keyboard input for both primary and secondary messages.
Innovation Solution
A dual-modulated QR code (DMQR) system uses intensity and orientation modulation with elliptical markers to encode primary and secondary messages, allowing close-range video cameras to decode the secondary message while preventing remote cameras from capturing it, by varying marker positions and orientations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional QR codes with square markers are used, then the primary message can be decoded by any video camera, but the secondary message becomes vulnerable to remote video camera capture
Solution Approach 1:
The patent transitions from encoding only positional information (2D location) to encoding both positional and orientational information (adding orientation dimension). The elliptical markers can be rotated to different angles, creating a new dimension of information encoding that allows the secondary message to be securely transmitted only when the marker orientation can be resolved, which requires close proximity viewing.
Solution Approach 2:
The patent changes the geometric parameters of the markers from square to elliptical shape, and introduces orientation as a variable parameter. The elliptical markers have specific aspect ratios and rotation angles that encode the secondary message. This parameter change enables the system to differentiate between close-range viewing (where orientation is visible) and remote viewing (where orientation becomes indistinguishable).
2Reliability
If elliptical markers with orientation modulation are used, then the secondary message can be secured from remote cameras, but the decoding complexity increases
Solution Approach 1:
The patent incorporates synchronization patterns and alignment markers in the QR code structure that are processed first to establish the coordinate system and orientation reference before attempting to decode the elliptical marker orientations. This preliminary action simplifies the subsequent orientation detection by providing a known reference framework.
Solution Approach 2:
The decoding system uses feedback mechanisms to iteratively refine the orientation measurements of the elliptical markers. The system captures the QR code image, detects the elliptical markers, estimates their orientations, decodes the secondary message, and can verify the decoding success. This feedback loop helps in accurately determining marker orientations even in challenging viewing conditions.
3Reliability
If the marker area is reduced to enable orientation detection, then the secondary message security improves, but the primary message detection reliability decreases
Solution Approach 1:
The patent applies different quality characteristics to different parts of the QR code structure. The synchronization patterns and alignment markers use large, high-contrast square modules for reliable detection at any distance. The data-encoding elliptical markers use smaller areas with specific orientation properties for secure secondary message transmission. This local differentiation allows each component to optimize its function without compromising the whole system.
Data Source
AI summary
A dual-modulated QR code (DMQR code) is in the format of a conventional QR code but uses elongated markers instead of black squares in the code modules. The positions of the markers within the DMQR code represent a nonconfidential primary message, and the orientations of the markers within the modules of the DMQR code represent a confidential secondary message.