Reversible Image Redaction via Encrypted Metadata Scrambling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing image redaction methods are permanent and irreversible, failing to provide a means to restore sensitive information from redacted images.

Innovation Solution

A reversible redacting method that scrambles sensitive portions of an image, allowing the original information to be restored by reverse-scrambling, with the scrambling arrangement recorded and encrypted in the image metadata.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If permanent redaction methods are used to protect sensitive information, then security is improved, but the ability to restore original information is lost

Engineering Contradiction:
ImprovesecurityVSAvoidrestorability
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent applies parameter changes by transforming the redaction method from permanent destruction to reversible transformation. The sensitive information is scrambled using a deterministic algorithm with a secret key, changing the state of the data from intelligible to unintelligible while preserving the possibility of restoration through the inverse operation with the key.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a scrambled copy of the sensitive information rather than destroying the original. The scrambling process generates an unintelligible version that contains all the information needed for restoration, allowing the original data to be recovered when the secret key is available.

Inventive Principle:
Principle #26Copying

2Loss of information

If scrambling arrangements are stored in metadata to enable restoration, then restorability is improved, but security is weakened

Engineering Contradiction:
ImproverestorabilityVSAvoidsecurity
Core Design Contradiction:
Loss of informationVSReliability

Solution Approach 1:

The patent embeds the scrambling arrangement (secret key or transformation parameters) within the image file itself, nested in the metadata or header sections. This allows the restoration information to be self-contained with the image data, enabling independent restoration without external storage dependencies.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent uses the image metadata as an intermediary to store the scrambling arrangement. This intermediary structure allows the secret information to be associated with the image without being directly visible or accessible, providing a balanced solution between restorability and security.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If multiple source images are processed with different scrambling arrangements, then security is improved, but processing complexity increases

Engineering Contradiction:
ImprovesecurityVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by processing each source image independently with its own scrambling arrangement. This divides the overall processing task into separate, manageable units, where each image can be scrambled and restored using the same algorithm but with different parameters, maintaining consistency while enabling individualized security.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3926938B1A system and a method for processing an image
Publication Date: 2025.02.26 IQ WORKS LTD
  • EP3926938B1 patent drawingFigure 1
  • EP3926938B1 patent drawingFigure 2
  • EP3926938B1 patent drawingFigure 3A~3C

AI summary

A system and a method for processing an image. The method comprises the steps of: receiving a source image having at least one sensitive portions arranged to present intelligible sensitive information; and processing, with a predetermined redacting method, the at least one sensitive portions of the source image to generate an output image including the intelligible sensitive information being transformed into an unintelligible form; wherein the sensitive information in the unintelligible form is adapted to be restored to an intelligible form.