Metastable Metal Particle Keys With Photon-Written Timed Decay
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current Physical Unclonable Functions (PUFs) face challenges such as fabrication complexity, high sensitivity, and lack of long-term stability, limiting their real-world applications, while metals have not fully utilized their potential as physical information storage carriers due to inherent compositional entropy.
Innovation Solution
The use of metastable metal particles, fabricated through photon stimulation, forms a grid with tunable patterns that carry predefined information, utilizing phase relaxation as a physical timer triggered by external perturbations, offering multiple decryption pathways and high entropy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current Physical Unclonable Functions are used, then encryption functionality is provided, but fabrication complexity and high sensitivity limit real-world applications
Solution Approach 1:
The patent changes the physical state parameter of metal particles from stable to metastable, enabling them to exist in an undercooled state that can be triggered to change phase. This parameter change allows the system to achieve both stability during storage and controlled transformation during operation, resolving the contradiction between long-term stability and functional responsiveness.
Solution Approach 2:
The patent utilizes phase transitions in metastable metal particles, where particles transition from an undercooled metastable state to a stable crystalline state upon triggering. This phase transition mechanism provides a reliable, repeatable physical process that enhances long-term stability while maintaining controlled transformability, directly addressing the reliability issue in current PUFs.
2Manufacturing precision
If metastable metal particles are used with photon stimulation, then high-resolution encryption patterns are formed, but multiple parameters must be precisely controlled
Solution Approach 1:
The patent employs laser photons that serve multiple functions simultaneously: they stimulate phase change in metastable particles, enable pattern formation through selective heating, and provide spatial resolution through beam focusing. This multi-functionality reduces the need for separate control mechanisms for each function, thereby managing complexity while achieving high manufacturing precision.
Solution Approach 2:
The patent replaces complex mechanical control systems with optical control using laser photons. The laser provides non-contact, precise spatial and temporal control of the phase change process, eliminating the need for mechanical actuators, contact probes, or complex positioning mechanisms, thus achieving high precision with reduced control parameter complexity.
3Reliability
If physical timer is initiated by external mechanical perturbation, then predictable decay rate is achieved, but sensitivity to external interference increases
Solution Approach 1:
The patent creates a dynamic system where the metastable particles can transition from a stable undercooled state to a transforming state upon receiving a trigger signal. The system remains dormant and insensitive during storage, then becomes responsive and predictable during operation. This dynamic behavior allows the physical timer to achieve predictable decay rates while minimizing sensitivity to unwanted external interference during the storage phase.
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
This approach provides a secure, high-resolution encryption process with tunable patterns, resistant to interference, and a physical timer that decays predictably, enhancing security and stability beyond conventional PUFs.
Implementation Method 1
inducing particle coalescence and growth of individual metastable metal particles through photon stimulation thereby forming a point-based pattern
Implementation Method 2
initiating a physical timer of the grid of metastable metal particles by application of an external mechanical perturbation thereby triggering a phase relaxation of the individual metastable metal particles. The phase relaxation can decay at a predictable rate.
Implementation Method 3
The photon stimulation can be provided by a tunable power laser diode. Power of the laser can determine information density at each spot of the grid of metastable metal particles.
Data Source
AI summary
Various examples are provided related to physically-timed keys. In one example, a method to provide a physically-timed physical unclonable function key includes providing a grid of metastable metal particles on undercooled metal particles; and inducing particle coalescence and growth of individual metastable metal particles through photon stimulation thereby forming a point-based pattern in the grid of metastable metal particles. Each point in the grid of metastable metal particles can carry predefined information or bear a specified information density. The method can further include initiating a physical timer of the grid of metastable metal particles by application of an external mechanical perturbation thereby triggering a phase relaxation of the individual metastable metal particles.