Auxiliary Current-Masking Circuit for Logic Power Analysis Resistance

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Solution Overview

Problem

Existing solutions for masking current consumption in integrated circuits are either restrictive, complex, or costly, and fail to effectively focus on logic circuits while maintaining simplicity and efficiency.

Innovation Solution

An auxiliary circuit within the integrated circuit that uses capacitors and switches controlled by a random signal generator to modify current consumption profiles, allowing for random attenuation, increase, or diversion of current, thereby masking real current consumption patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the dual rail technique is used to mask current consumption, then current consumption is masked, but the surface area increases and logic gates are doubled

Engineering Contradiction:
Improvecurrent consumption maskingVSAvoidsurface area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The invention divides the circuit into two separate paths: a first path carrying the actual logic circuit current and a second path carrying a compensating current. This segmentation allows independent control of each path's current characteristics, enabling masking of the logic circuit's consumption profile without duplicating all logic gates, thus reducing surface area compared to dual rail technique

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces a compensating current path as an intermediary element that generates a current profile opposing the logic circuit's consumption. This mediator current masks the actual consumption without requiring physical duplication of logic gates, resolving the contradiction between masking effectiveness and surface area

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If existing solutions are used to mask current consumption without masking other components, then current consumption is masked, but the complexity increases and numerous components are required

Engineering Contradiction:
Improvecurrent consumption maskingVSAvoidcomplexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention applies current masking locally to specific logic circuits rather than globally to the entire integrated circuit. The compensating current path is configured to match only the consumption profile of the target logic circuit, allowing selective masking of vulnerable components while leaving other components unaffected, thereby reducing overall system complexity

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The compensating current path uses dynamic control elements (switches and capacitors) that can be configured through programming to match different logic circuit consumption profiles. This dynamic adaptability allows the same hardware structure to mask different circuits without requiring dedicated components for each, reducing device complexity

Inventive Principle:
Principle #15Dynamics

3Ease of manufacture

If conventional production methods are used, then manufacturing is simple and efficient, but current consumption patterns may be more vulnerable to analysis

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidresistance to power analysis
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention changes the electrical parameters of the circuit by introducing variable resistance and capacitance elements in the compensating current path. These parameters can be programmed to different values to create diverse current consumption profiles, making power analysis attacks difficult while maintaining compatibility with conventional production methods for fabricating standard electronic components

Inventive Principle:
Principle #35Parameter changes

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 solution effectively masks current consumption patterns, making it difficult for attackers to analyze the behavior of the integrated circuit through simple and efficient means, using conventional production methods and minimizing computational overhead.

Implementation Method 1

An auxiliary circuit within the integrated circuit that uses capacitors and switches controlled by a random signal generator to modify current consumption profiles

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3483773B1Method for randomly modifying the consumption profile of a logic circuit, and associated device
Publication Date: 2020.07.08 STMICROELECTRONICS (ROUSSET) SAS
  • EP3483773B1 patent drawingFigure 1~2
  • EP3483773B1 patent drawingFigure 3~4
  • EP3483773B1 patent drawingFigure 5~6

AI summary

Electronic circuit comprising a supply terminal (BV) and a reference terminal (BR), comprising at least one module (M) comprising at least one logic circuit (CL) coupled between the supply terminal (BV) and the reference terminal (BR) and comprising an output terminal (BS), and at least one auxiliary circuit (Cx) coupled between the supply terminal (BV) and the reference terminal (BR), and coupled to the output terminal (BS), said at least one auxiliary circuit (Cx) being configured to perform at least one action taken from the group formed by - a reduction of the current flowing between the supply terminal (BV) and the reference terminal (BR), - an increase of the current flowing between the supply terminal (BV) and the reference terminal (BR), - the flow of additional current on a path not passing through the supply terminal (BV), or to perform no action.