Jitter Detection for Semiconductor Secure Element EMFI

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Solution Overview

Problem

Existing technologies fail to effectively detect Electromagnetic-Fault-Injection (EMFI) attacks on secure semiconductor circuits, which can compromise security by inducing timing violations, and are not well represented by traditional timing fault models, requiring early detection sensitive to low EM levels yet robust to avoid false error reporting.

Innovation Solution

A method and apparatus for detecting EMFI attacks by generating a test pulse in a secure element, measuring disturbances using a jitter measurement circuit, and comparing the measured jitter or glitch against a reference to identify EMFI events, utilizing a Time to Digital Converter (TDC) and comparator circuit to determine and respond to such attacks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional timing fault models are used for detection, then the detection mechanism is simple, but the detection precision is insufficient for EMFI attacks

Engineering Contradiction:
Improvedetection precisionVSAvoiddetection mechanism complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces traditional timing fault detection models with a sampling fault model that uses jitter measurement circuits and Time-to-Digital Converters (TDC) to detect EMFI attacks. This substitution enables precise measurement of temporal disturbances caused by electromagnetic interference, achieving high detection precision while maintaining practical device complexity through integrated circuit implementation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If the detection mechanism is made sensitive to low EM levels, then the detection capability improves, but false error reporting increases due to power supply variations and noise

Engineering Contradiction:
Improvedetection reliabilityVSAvoidfalse error rate
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a feedback mechanism where the jitter measurement circuit continuously monitors temporal disturbances and compares them against reference values. The system uses the measured jitter information to adjust detection thresholds and distinguish between genuine EMFI attacks and normal operational variations, thereby reducing false error rates while maintaining sensitivity to low-level electromagnetic interference.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces a jitter measurement circuit and TDC as intermediary components between the secure element and the detection logic. These intermediaries convert complex electromagnetic disturbances into measurable temporal parameters (jitter values), enabling reliable detection while filtering out noise and power supply variations through controlled measurement processes.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If early detection of EMFI attacks is implemented, then security is improved, but the device footprint and power consumption increase

Engineering Contradiction:
ImprovesecurityVSAvoiddevice footprint
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent merges the jitter measurement circuit, TDC, and detection logic into an integrated structure that shares resources with the secure element's existing timing infrastructure. By combining multiple detection functions into a unified circuit block, the system achieves early EMFI detection capability while minimizing the additional footprint and power consumption compared to separate dedicated detection modules.

Inventive Principle:
Principle #5Merging (Combining)

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

Provides early detection of EMFI attacks with a small footprint, fast response, low false error rate, and tolerance to power supply noise, manufacturing variations, and environmental effects, ensuring secure data retention.

Implementation Method 1

An EMFI attack couples Electromagnetic (EM) energy into power and ground loops of a circuit to induce timing violations in a specific location proximal to the EM source

Methodology Applied
Scientific EffectElectromagnetic coupling: Electromagnetic Induction

Implementation Method 2

A temporal change between the test pulse and the observed pulse is measured to determine an Electromagnetic-Fault-Injection (EMFI) event

Methodology Applied
Scientific EffectTime-to-Digital Conversion:

Data Source

PatentEP4575534A1Jitter applied detection for semiconductor secure element
Publication Date: 2025.06.25 NXP BV
  • EP4575534A1 patent drawingFigure 1
  • EP4575534A1 patent drawingFigure 2
  • EP4575534A1 patent drawingFigure 3

AI summary

A method for jitter applied detection for a semiconductor secure element including generating a test waveform comprising a test pulse. The test waveform is modulated with an inductive loop coupled to a secure element and to an Electromagnetic (EM) signal to generate an observed waveform comprising an observed pulse, wherein the secure element comprises a flip-flop. A temporal change is measured between the test pulse and the observed pulse and the temporal change is compared to a reference to determine an Electromagnetic-Fault-Injection (EMFI) event.