Fault Injection Detector Circuit for Integrated Circuits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated circuits face challenges in protecting against laser scanning-based fault injection attacks without increasing the surface area of the chip, which compromises their security and functionality.
Innovation Solution
A fault detection circuit is implemented with an isolation block that applies a signal during functional phases and a forced value during detection phases, using multiplexers and delay elements to enhance sensitivity and detect changes in output signals, thereby improving fault detection capabilities without expanding the chip's surface area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of detectors in the surface of the circuit is increased to improve protection against fault injection attacks, then the security level is improved, but the surface area of the chip increases
Solution Approach 1:
The patent makes logic blocks perform dual functions: during functional phases they execute normal logic operations, and during detection phases they serve as fault detectors by monitoring their own output signals. This eliminates the need for separate dedicated detector circuits, thereby improving security without increasing chip surface area.
Solution Approach 2:
The patent dynamically switches logic blocks between functional mode and detection mode using phase signals. During detection phases, the same logic blocks that process data normally are temporarily configured to monitor their own outputs for fault conditions. This dynamic reconfiguration allows the circuit to have detector capability proportional to its functional capacity without requiring additional static detector resources.
2Measurement precision
If more detectors are distributed in the circuit surface to improve fault detection capacity, then the detection capability is improved, but the effective area available for implementing intended functions decreases
Solution Approach 1:
Logic blocks serve both as functional units implementing the circuit's intended operations and as fault detectors monitoring their own outputs. The same hardware resources are reused for both purposes at different times, maximizing the effective area available for intended functions while maintaining comprehensive fault detection coverage.
Solution Approach 2:
Each logic block monitors its own output signals for fault conditions rather than requiring separate external detectors. This self-service approach eliminates the need for additional detector circuits and allows the logic blocks to detect faults in themselves, thereby preserving all chip area for functional purposes.
3Reliability
If detection circuits are added to monitor logic block outputs for fault conditions, then the reliability against attacks is improved, but the device complexity increases
Solution Approach 1:
Logic blocks autonomously monitor their own output signals for fault conditions using their existing internal logic and output structures. No additional monitoring circuits or external detectors are required, as each block serves itself by detecting faults in its own operation, thereby avoiding any increase in device complexity.
Solution Approach 2:
The fault detection function is extracted from the concept of requiring separate dedicated detector circuits and is instead integrated into the existing logic block operations. By taking the detection capability from a separate component and embedding it within the logic blocks themselves, the overall device complexity remains unchanged while protection against attacks is improved.
Data Source
Figure 1~3A
Figure 3B~5
Figure 6~8
AI summary
The invention relates to a circuit for detecting fault injection into an integrated circuit comprising: at least one logic block (202) for executing a logic function of the integrated circuit; an isolation block (204), connected to receive a signal to be processed (208) as well as an isolation activation signal indicating a functional phase and a fault detection phase of the first block, the isolation block applying, during said functional phase, said signal to be processed to at least one input of the logic block and, during said detection phase, a forced value to said input of the logic block; and a detection block (212) capable of detecting, during said detection phase, a change in an output signal of the logic block.