Coil Active Shield Structure for EM Side-Channel Masking

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Solution Overview

Problem

Conventional active shields are inadequate in preventing electro-magnetic side channel analysis attacks, as they do not effectively mask electromagnetic leakage from internal logic operations, leaving sensitive circuitry vulnerable to unauthorized access and tampering.

Innovation Solution

The implementation of a coil-based active shield structure that generates a strong electromagnetic signature to mask internal logic operations, combining physical tamper protection with electromagnetic countermeasures, using coil-shaped metal lines to create a noisy electromagnetic environment and prevent unauthorized access by generating an alarm signal upon tampering attempts, without increasing circuit area or power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If standard active shields are used, then physical tamper protection is provided, but electromagnetic side channel attacks are not prevented

Engineering Contradiction:

Improvetamper protectionVSAvoidelectromagnetic leakage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent combines physical tamper protection and electromagnetic shielding into a single integrated active shield structure. The coil-shaped metal lines perform dual functions: detecting physical tampering through signal interruption and generating electromagnetic noise to mask side-channel attacks, eliminating the need for separate protection mechanisms.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The active shield structure is designed to provide multiple protection functions simultaneously. The same coil-shaped metal lines that detect physical cuts also generate electromagnetic interference to prevent electromagnetic analysis attacks, making the shield universal against multiple attack vectors.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Object-affected harmful factors

If coil-shaped metal lines are added to enhance electromagnetic protection, then electromagnetic masking is improved, but circuit area increases

Engineering Contradiction:

Improveelectromagnetic maskingVSAvoidcircuit area

Core Design Contradiction:

Object-affected harmful factorsVSArea of stationary object

Solution Approach 1:

The patent utilizes the vertical dimension by placing coil-shaped metal lines in upper metal layers above the sensitive circuitry. This allows the shield to cover a larger horizontal area while occupying minimal additional chip real estate, as the coils extend vertically through multiple metal layers rather than spreading horizontally in a single layer.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The use of coil-shaped (curved) metal lines instead of straight lines increases the effective length of the shield within a compact area. The curved path allows the shield to cover more perimeter and generate stronger electromagnetic fields without proportionally increasing the area occupied.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Measurement precision

If tighter pitch metal lines are used, then tamper detection sensitivity is improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improvetamper detection sensitivityVSAvoidline pitch control

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The active shield is divided into multiple sequential coil segments along the metal line path. Each segment acts as an independent detection zone, allowing the shield to maintain high sensitivity without requiring the entire line to be at minimum pitch. The segmented structure provides redundancy and reduces the impact of manufacturing variations in any single segment.

Inventive Principle:

Principle #1Segmentation

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 coil-based active shield effectively protects sensitive circuitry from both physical tampering and electromagnetic side channel attacks, enhancing security without additional circuit area or power consumption, ensuring robust tamper protection and confidentiality of cryptographic operations.

Implementation Method 1

coil-based active shield structure that generates a strong electromagnetic signature to mask internal logic operations

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

using coil-shaped metal lines to create a noisy electromagnetic environment

Methodology Applied

Scientific EffectElectromagnetic radiation:

Data Source

PatentUS20250016968A1Active Shield Structure

Publication Date: 2025.01.09 ARM LTD

AI summary

Various implementations described herein are related to a device having a first coil-shaped spiral structure for an active shield and a second coil-shaped spiral structure that is wound in-between windings of the first coil-shaped spiral structure. The first coil-shaped spiral structure may provide for a coil-based electro-magnetic (EM) shield as a counter-measure circuit for protecting an underlying circuit.