PUF Helper Data Reduction via Reliable Cell Group Addressing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing physical unclonable function (PUF) devices require significant on-chip storage for helper data, which is a challenge in devices without non-volatile memory like flash or EEPROM, as they need to store addresses of reliable cells to generate stable secret information.
Innovation Solution
A PUF device with an array of cells, a reliable cell group detector, and a storage device that identifies and stores addresses of reliable cell groups, blocks, or patterns to reduce the size of helper data by selecting only reliable cells for secret information generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If addresses of all reliable cells are stored as helper data, then secret information can be reliably reconstructed, but the storage size required on-chip becomes too large for devices without non-volatile memory
Solution Approach 1:
The patent divides the array of cells into multiple groups and selects one group containing sufficient reliable cells for secret information generation. This segmentation approach reduces the number of cells that need to be monitored and stored, thereby reducing helper data size while maintaining reconstruction reliability.
Solution Approach 2:
The patent extracts and stores only the address of the selected group of reliable cells rather than storing information about all reliable cells in the array. This extraction of essential information (group address vs. individual cell addresses) significantly reduces the helper data storage requirements.
2Loss of information
If a bitmap of all cells is stored to indicate which cells are good, then cell selection information is complete, but the helper data size becomes excessively large
Solution Approach 1:
Instead of creating a bitmap for every individual cell, the patent segments the cell array into groups and creates a bitmap only for the selected group. This reduces the bitmap size from covering all cells to covering only the necessary subset, thereby reducing helper data size while preserving essential cell selection information.
Solution Approach 2:
The patent extracts only the essential information needed for reconstruction (the group address and its bitmap) rather than storing complete cell selection data for the entire array. This extraction eliminates redundant information while maintaining the ability to reliably reconstruct secret information.
Data Source
AI summary
Embodiments of a physical unclonable function (PUF) device and a method for generating helper data for a PUF device with an array of cells are disclosed. In an embodiment, the PUF device comprises an array of cells, wherein each cell of the array generates an output signal, a reliable cell group detector coupled to the array of cells to find reliable groups of cells in the array of cells having sufficient reliable cells and output addresses of the reliable groups of cells, and a storage device coupled to the reliable cell group detector to store the addresses of the reliable groups of cells to be used as helper data for PUF response operations.