PUF Generator Characterization via BIST Stability Mapping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for a method to characterize physically unclonable function (PUF) generators efficiently for quality control, enabling the identification of defective units, categorization of qualified ones, and insight into manufacturing processes at high speed and low cost.
Innovation Solution
The proposed solution involves a PUF generator system with a PUF cell array, a controller, and a Built-in Self Test (BIST) engine, which generates masking and golden maps to identify stable and unstable bit cells, and uses these maps to filter PUF outputs, ensuring only stable bit cells contribute to the PUF signature, thereby ensuring repeatability and uniqueness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional authentication methods inscribing identity on devices are used, then implementation is simple, but security is compromised as identities can be mimicked and reverse engineered
Solution Approach 1:
The patent applies preliminary action by pre-characterizing PUF generators during manufacturing to extract unique physical signatures before deployment. This pre-established identity binding to physical properties enables secure authentication without requiring complex runtime verification mechanisms, as the unique identity is inherently tied to the device's physical characteristics from fabrication
2Productivity
If PUF generator testing is performed at high speed for quality control, then productivity improves, but measurement precision may deteriorate
Solution Approach 1:
The patent performs preliminary characterization of PUF generators during manufacturing to establish baseline performance metrics and unique signatures. By pre-establishing these references before deployment, the system enables rapid quality control testing without sacrificing accuracy, as the pre-captured physical characteristics serve as authoritative references for subsequent fast comparisons
Solution Approach 2:
The patent creates digital copies of the PUF generator's unique physical characteristics through challenge-response pair extraction during manufacturing. These copied signatures are stored and used for rapid authentication and quality control, enabling high-speed verification without repeatedly measuring the physical device, thus maintaining precision while improving productivity
Data Source
AI summary
Disclosed is a physical unclonable function generator circuit and testing method. In one embodiment, a testing method for physical unclonable function (PUF) generator includes: verifying a functionality of a PUF generator by writing preconfigured logical states to and reading output logical states from a plurality of bit cells in a PUF cell array; determining a first number of first bit cells in the PUF cell array, wherein the output logical states of the first bit cells are different from the preconfigured logical states; when the first number of first bit cells is less than a first predetermined number, generating a first map under a first set of operation conditions using the PUF generator and a masking circuit, generating a second map under a second set of operation conditions using the PUF generator and the masking circuit, determining a second number of second bit cells, wherein the second bit cells are stable in the first map and unstable in the second map; when the second number of second bit cells is determined to be zero, determining a third number of third bit cells, wherein the third bit cells are stable in the first map and stable in the second map; and when the third number of third bit cells are greater than a second preconfigured number, the PUF generator is determined as a qualified PUF generator.