Attack Detection Circuit for Multi-Bit Laser Faults in ICs
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Solution Overview
Problem
Current methods for protecting semiconductor integrated circuits against laser attacks, such as light detectors and circuit duplexing, face challenges with detecting smaller laser beam diameters and increasing chip costs, as well as limitations in error detection codes that can only detect single-bit errors, failing to effectively cope with multi-bit errors beyond their theoretical detection limits.
Innovation Solution
An attack detection circuit is implemented, combining an error determination circuit capable of detecting k-bit or less errors through logic operations and a light irradiation detection circuit with strategically arranged light detection elements to detect errors beyond the detection limit of the error determination circuit, ensuring comprehensive detection of laser attacks on multi-bit storage elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If light detection elements are disposed at light irradiation positions to directly detect laser attacks, then detection capability is improved, but chip area and cost increase
Solution Approach 1:
The patent combines light detection elements with existing transistor structures in the semiconductor circuit. Specifically, photodiodes are integrated into the substrate beneath or alongside transistor components, allowing the light detection function to be merged with the existing circuit layout without requiring separate dedicated detection areas, thus improving detection capability while minimizing additional chip area occupation.
Solution Approach 2:
The patent makes the semiconductor circuit components serve multiple functions. The transistor structures and substrate serve both their original computational/storage functions and additionally function as light detection elements. This multi-functionality allows the same physical structures to detect laser attacks while maintaining their primary circuit operations, reducing the need for separate detection hardware and associated chip area.
2Reliability
If error detection codes are used to detect faults, then detection capability is improved, but they can only detect single-bit errors and fail beyond theoretical detection limits
Solution Approach 1:
The patent segments the detection capability into two complementary parts: error detection codes handle single-bit errors within theoretical detection limits, while light detection elements handle multi-bit errors beyond those limits. This segmentation allows each mechanism to operate within its optimal range, with the light detection providing additional coverage for severe attacks that would overwhelm traditional error correction codes alone.
Solution Approach 2:
The patent creates a composite detection system combining two different detection mechanisms: traditional error detection codes (software/logic-based) and photodiode-based light detection (physical/optical-based). This composite approach leverages the strengths of both methods, where error codes provide efficient single-bit detection and light detection provides robust multi-bit and direct laser attack detection, achieving comprehensive error detection coverage beyond what either method could achieve alone.
3Reliability
If circuit duplexing is implemented to detect laser attacks, then detection capability is improved, but chip area and manufacturing cost increase significantly
Solution Approach 1:
The patent extracts the light detection function from separate dual circuit implementations and integrates it directly into the substrate beneath existing single circuit elements. Instead of duplicating entire circuits for detection purposes, the photodiodes are taken out as separate detection components that monitor the physical state of the underlying transistors, providing attack detection without requiring full circuit duplication and associated manufacturing complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables the detection of laser attacks irrespective of the number of error bits in multi-bit storage elements, providing robust protection against laser attacks without significantly increasing chip size or cost, and effectively handling errors beyond the theoretical detection limits of traditional error detection codes.
Implementation Method 1
a light detection element, that is, a photodiode
Data Source
AI summary
A semiconductor integrated circuit includes a logic circuit, the logic circuit including an attack detection circuit for checking multi-bit storage. The attack detection circuit includes an error determination circuit capable of detection through a logic operation such as a code theory and a light irradiation detection circuit having light detection elements, and the light detection elements are arranged so that the light irradiation detection circuit can detect errors of the number of bits beyond the detection limit of the error determination circuit. Due to error detection by the error determination circuit and light irradiation detection by the light irradiation detection circuit, the circuits complementarily detect fault attacks from outside.