Processing Device Active Attack Protection via Data Infection

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Solution Overview

Problem

Existing cryptographic systems are vulnerable to both passive and active attacks, as they fail to effectively prevent the extraction of sensitive data, such as encryption keys, through physical attacks that analyze system characteristics or disrupt operations.

Innovation Solution

A method that divides data processing into multiple functions, where each function application is executed simultaneously with an attack detection step, and if an attack is detected, the intermediate data is infected with random or null values, making it difficult for attackers to isolate processing steps and correlate output data with device behavior.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If encryption duplication is carried out in parallel to protect against active attacks, then security against active attacks is improved, but the noise-to-signal ratio becomes observable and usable by attackers through passive attacks

Engineering Contradiction:
Improveprotection against active attacksVSAvoidpassive attack vulnerability
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the encryption operation into multiple intermediate processing steps (at least two intermediate results) that are computed sequentially. Each intermediate result is verified against expected values before proceeding to the next step. This segmentation allows the system to detect active attacks at intermediate stages while avoiding the parallel execution that creates observable noise patterns for passive attacks.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary verification of intermediate results during the encryption process. Before completing the full encryption operation, the system checks intermediate values against pre-computed expected values. This preliminary action enables early detection of active attacks without requiring parallel execution, thus avoiding passive attack vulnerabilities while maintaining active attack protection.

Inventive Principle:
Principle #10Preliminary action

2Object-affected harmful factors

If encryption duplication is carried out in series to avoid doubling power consumption, then passive attack vulnerability is reduced, but the attacker can make active attacks at multiple possible times

Engineering Contradiction:
Improvepassive attack vulnerabilityVSAvoidprotection against active attacks
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent divides the encryption process into multiple segmented steps with verification points in between. Each segment produces an intermediate result that is verified against expected values. This segmentation transforms a single vulnerable series execution into multiple controlled stages, maintaining the sequential power consumption profile while limiting active attack effectiveness at each stage through verification.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements feedback mechanisms where intermediate results are verified against expected values before proceeding. This feedback loop provides continuous monitoring throughout the sequential encryption process, enabling detection of active attacks at any intermediate stage while maintaining the power-efficient sequential execution structure.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If attack detection is performed after each processing function to improve detection speed, then active attack detection capability is improved, but the processing time increases due to multiple verification steps

Engineering Contradiction:
Improveattack detection accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs verification only at intermediate stages rather than continuously monitoring every operation. By selecting specific intermediate results for verification against expected values, the system achieves effective attack detection without the overhead of continuous verification, thus reducing the time penalty while maintaining detection accuracy.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP2805228B1Method for protection from active attacks and device using the method
Publication Date: 2016.09.07 CASSIDIAN CYBERSECURITY
  • EP2805228B1 patent drawingFigure 1
  • EP2805228B1 patent drawingFigure 2

AI summary

Processing device implementing a method for protecting the processing (AG) of sensitive data, intended for processing sensitive input data (DE) in order to obtain sensitive output data (DS), wherein data processing is divided into at least two processing functions (f, g). The device comprises: - a processing entity (ET) for successively applying the processing functions from sensitive input data, and obtaining the sensitive output data after applying the last processing function, and - a protection entity (EP) for detecting an attack simultaneously with each application of a processing function, and infecting the data resulting from the application of each processing function if an attack is detected.