Robust Optical Physical Unclonable Function Based on Total Internal Reflection for Portable Authentication

Area of Science:

• Optoelectronics
• Materials Science
• Cryptography

Background:

• Current optical Physical Unclonable Functions (PUFs) rely on materials with inherent robustness issues.
• Manufacturing randomness is key for PUF-based cryptographic primitives.
• There is a need for stable and reliable optical PUF solutions.

Purpose of the Study:

• To develop an environmentally stable optical PUF using total internal reflection (TIR).
• To enhance security and reliability for cryptographic applications.
• To demonstrate the feasibility of portable authentication systems.

Main Methods:

• Constructed a TIR-PUF by perturbing total internal reflection with randomly distributed polymer microspheres.
• Optimized polymer solution concentration to improve bit uniformity and encoding capacity.
• Developed an iterative binning procedure to transform response images into encoded keys.

Main Results:

• Achieved high encoding capacity (2^370) and extremely low authentication error probability (1.614 × 10^-23).
• Demonstrated excellent readout reliability with a low intra-Hamming distance (0.068).
• Confirmed significant environmental stability under ultrasonic washing, high temperature, UV irradiation, and chemical exposure.

Conclusions:

• The developed TIR-PUF offers superior environmental stability and security compared to existing optical PUFs.
• The system's performance indicates suitability for practical, portable authentication applications.
• This work paves the way for robust, low-power, and wireless authentication solutions.