Masked PUF Error Correction Using a Secure ECC Subsystem
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated circuits with Physically Unclonable Function (PUF) circuits face challenges in error correction, as conventional methods require exposing sensitive PUF output to generic processors for error correction, potentially compromising security due to noise and variation changes over time.
Innovation Solution
A secure subsystem within the integrated circuit includes a PUF circuit, a random generator, non-volatile memory for storing syndromes, and a syndrome generator, which masks the PUF response and syndrome to protect sensitive information, allowing error correction using a generic non-secure ECC processor without revealing the raw PUF output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional error correction methods are used on PUF output, then error correction capability is improved, but security is worsened due to exposure of sensitive PUF output to generic processors
Solution Approach 1:
The patent introduces an intermediary masking mechanism where random values are XORed with the PUF output and syndrome bits before being passed to the generic ECC processor. This intermediary layer protects the sensitive PUF output from direct exposure while still enabling error correction functionality.
Solution Approach 2:
The patent segments the error correction process into two distinct parts: a secure subsystem that handles sensitive PUF output and generates masked data, and a generic ECC processor that performs error correction on the masked data. This segmentation allows each component to operate in its optimal security and functional environment.
2Reliability
If PUF output is passed to generic processor for error correction, then error correction is achieved, but secret information may be accessed by unauthorized party
Solution Approach 1:
The masking mechanism using random values serves as an intermediary that prevents direct access to secret PUF output by the generic processor. The random values are combined with the PUF output and syndrome bits, creating protected representations that maintain error correction capability while preventing information leakage.
Solution Approach 2:
The patent creates masked copies of the PUF output and syndrome bits rather than passing the original sensitive data to the generic processor. These copies contain the necessary error correction information but are obfuscated to prevent unauthorized access to the underlying secret information.
3Object-affected harmful factors
If masking is applied to PUF response and syndrome, then security is improved, but system complexity increases due to additional components
Solution Approach 1:
The generic ECC processor is made multi-functional by enabling it to handle both traditional error correction tasks and the specialized task of correcting masked PUF output. This universality allows the system to reuse existing error correction hardware while extending its capability to support secure PUF operations.
Solution Approach 2:
The secure subsystem performs self-service by generating the masking random values and applying the masking operation internally before passing data to the generic processor. This self-service approach minimizes the need for additional dedicated security hardware components.
Data Source
AI summary
An integrated circuit having a Physically Unclonable Function (PUF) circuit is provided. The PUF circuit may be part of a secure subsystem, which also includes a random number generator, a syndrome generator, non-volatile memory, and control circuitry. A predetermined syndrome of a desired PUF response is stored in the non-volatile memory. During normal operation, a current PUF response may be read out from the PUF circuit. The current PUF response may differ from the desired PUF response. The random number generator may generate a random number that masks the current PUF response, whereas the syndrome generator outputs a syndrome of the current PUF response. This information may then be passed to an error-correcting code (ECC) processor. The ECC processor may return information to the secure subsystem. The control circuitry may then obtain a corrected PUF response that matches the desired PUF response.