Asynchronous PUF Security Device Minimizing Blind Zone
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional security devices with physical unclonable functions (PUFs) face challenges in minimizing the blind zone during digital random signal validity detection due to synchronous configurations, which restrict the detection of signal transitions during clock deactivation periods.
Innovation Solution
The implementation of an asynchronous configuration for the security device, where the blind zone is minimized by reducing the duration of the reset signal being logic '1', and utilizing multiple entropy sources and digitizers connected through various combination units to generate and validate digital random signals, thereby reducing the area required for the PUF and enhancing entropy value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a synchronous configuration is used for validity detection, then the detection mechanism is simple to implement, but a blind zone is generated during clock deactivation periods preventing detection of digital random signal transitions
Solution Approach 1:
The patent inverts the conventional synchronous detection approach by using an asynchronous detection mechanism. Instead of relying on a synchronous clock signal that creates blind zones during deactivation, the invention detects transitions of the digital random signal continuously without being bound by clock cycles, thereby eliminating the blind zone problem while maintaining implementation feasibility
Solution Approach 2:
The patent introduces dynamic control of the reset signal duration to minimize the blind zone. By dynamically adjusting the period during which the reset signal is logic '1' to the minimum necessary duration, the system reduces the blind zone while maintaining the ability to detect signal transitions effectively
2Reliability
If multiple entropy sources and digitizers are used to increase entropy value, then the security strength is improved, but the area required for the PUF increases
Solution Approach 1:
The patent combines multiple entropy sources and digitizers into a unified PUF structure where they share common control and detection logic. By merging the control mechanisms and using shared resources for managing multiple entropy sources and digitizers, the system achieves high entropy value without proportionally increasing the device area
Solution Approach 2:
The patent implements universal control logic that can manage multiple entropy sources and digitizers through a single set of control circuits. The control mechanism is designed to be multi-functional, capable of selecting and managing different combinations of entropy sources and digitizers, thereby reducing the need for dedicated control hardware for each component
Data Source
AI summary
The inventive concept provides a security device capable of reducing an area of a die required for implementation of a stable PUF by increasing the value of entropy from a predefined number of entropy sources and/or minimizing a blind zone of a validity checking module. The security device uses an asynchronous configuration to minimize a blind zone. In various embodiments of the inventive concept, the blind zone is generated only in a period when a reset signal is at a first logic level. Therefore, it is possible to minimize the blind zone by minimizing a period in which the reset signal is at such logic level. A semiconductor device, semiconductor package, and/or smart card can be provided with such security device, as well as a method for determining a validity of a random signal using a semiconductor security device.