Electromagnetic Fault Injection Detection Circuit for Security Chips

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Solution Overview

Problem

There is an urgent need for a detection circuit that can detect electromagnetic fault injection in real time to ensure the robustness and safety of security chips, as existing technologies are vulnerable to electromagnetic fault injection attacks that can cause abnormal working states and leakage of confidential data.

Innovation Solution

A detection circuit incorporating a shielding layer, metal-oxide semiconductor (MOS) transistors, latches, and a signal output module that generates target signals based on voltage changes to indicate the presence or absence of electromagnetic fault injection, thereby detecting and alarming such events in real time, while simplifying the circuit structure and reducing power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electromagnetic fault injection is used to attack the chip, then confidential data can be obtained, but the security and robustness of the chip deteriorates

Engineering Contradiction:
Improvechip securityVSAvoidelectromagnetic fault injection vulnerability
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a detection circuit that performs preliminary detection of electromagnetic fault injection attacks before they can compromise the chip. The circuit includes a shielding layer, MOS transistors, latches, and a signal output module that work together to detect abnormal voltage changes caused by electromagnetic injection, enabling early warning and prevention of data leakage.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary detection circuit between the chip core and the external electromagnetic environment. This circuit acts as a mediator that monitors voltage changes on the shielding layer and converts them into detectable signals, allowing the chip to sense electromagnetic attacks without directly exposing the confidential data storage areas.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a detection circuit is added to detect electromagnetic fault injection, then chip security is improved, but circuit complexity increases

Engineering Contradiction:
Improveelectromagnetic fault detection capabilityVSAvoiddetection circuit structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The detection circuit is segmented into distinct functional modules: a shielding layer for electromagnetic protection, MOS transistors for voltage sensing, latches for signal latching, and a signal output module for alarm generation. This segmentation allows each component to perform its specific function efficiently while maintaining overall circuit manageability and reducing design complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The detection circuit is designed to be integrated with the existing chip structure, where the shielding layer serves both as electromagnetic protection and as the sensing element for fault detection. The MOS transistors function as both switches and voltage sensors, and the latches serve both signal storage and amplification purposes, reducing the need for separate dedicated components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If real-time detection is implemented, then electromagnetic fault injection can be alarmed in time, but power consumption increases

Engineering Contradiction:
Improvereal-time detection accuracyVSAvoiddetection circuit power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The detection circuit employs periodic sampling of the voltage on the shielding layer through the MOS transistors, rather than continuous monitoring. The latches capture voltage states at specific moments, and the signal output module generates alarms only when abnormal states are detected, enabling real-time detection capability while significantly reducing average power consumption compared to continuous active monitoring.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The detection circuit leverages the existing voltage changes on the shielding layer caused by electromagnetic fault injection as the detection signal source. The MOS transistors automatically respond to voltage changes without requiring external stimulation, and the latches self-trigger based on detected anomalies, reducing the need for additional power-consuming active scanning mechanisms.

Inventive Principle:
Principle #25Self-service

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

The proposed detection circuit effectively detects electromagnetic fault injections in real time, ensuring the robustness and safety of security chips by outputting distinct signals for fault and non-fault conditions, thus preventing data leakage and maintaining chip integrity.

Implementation Method 1

a shielding layer configured to shield interference

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Implementation Method 2

the at least one group of MOS transistors is configured to detect whether an abnormal voltage occurs in the shielding layer

Methodology Applied
Scientific EffectVoltage detection: Electric Field

Data Source

PatentEP3812946B1Detection circuit for electromagnetic fault injection, security chip, and electronic device
Publication Date: 2022.01.19 SHENZHEN GOODIX TECH CO LTD
  • EP3812946B1 patent drawingFigure 1
  • EP3812946B1 patent drawingFigure 2~3
  • EP3812946B1 patent drawingFigure 4

AI summary

A detection circuit of electromagnetic fault injection, a security chip and an electronic device are provided. The detection circuit of electromagnetic fault injection includes: a shielding layer configured to shield interference; at least one group of metal-oxide semiconductor MOS transistors, where a source end of the at least one group of MOS transistors is connected to the shielding layer; at least one latch, where a drain end of the at least one group of MOS transistors is connected to an input end of the at least one latch; and a signal output module, where an input end of the signal output module is connected to an output end of the at least one latch. The detection circuit could detect in real time and alarm electromagnetic fault injection in time to ensure robustness and safety of a chip. In addition, the detection circuit of electromagnetic fault injection is designed based on the shielding layer, which could achieve the purposes of effectively simplifying a circuit structure, saving a circuit area, avoiding occurrence of static power consumption, reducing circuit costs, and the like.