HEIF File Encryption Key Nesting for Image Access Control

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Solution Overview

Problem

Existing file formats, such as HEIF, lack mechanisms to restrict the viewing of images stored within them, which can lead to issues related to copyright and portrait rights protection.

Innovation Solution

The implementation of a file processing device and method that enables the restriction of image viewing by associating encrypted images with encrypted encryption keys within an HEIF file, using a digital camera and external computer system to manage encryption keys.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If images are stored in HEIF file format for efficient storage, then storage efficiency is improved, but viewing restriction capability deteriorates (no built-in mechanism to restrict image viewing)

Engineering Contradiction:
Improvestorage efficiencyVSAvoidviewing restriction capability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent embeds encryption keys and viewing restriction data within the HEIF file structure itself. The encryption key is stored in a specific box structure (e.g., 'iprp' or custom box) within the file, creating a nested configuration where the file contains both the image data and the means to control its access. This resolves the contradiction by maintaining storage efficiency while adding viewing restriction capability through internal nesting of control mechanisms.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent introduces an encryption key as an intermediary element between the stored image and the viewer. The encryption key acts as a mediator that enables or disables access to the image content. By embedding this intermediary within the file structure, the system achieves viewing restriction without requiring external key management systems, thus maintaining storage efficiency while enabling reliability in access control.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If encryption keys are embedded within the HEIF file to enable viewing restriction, then viewing restriction capability is improved, but file structure complexity worsens

Engineering Contradiction:
Improveviewing restriction capabilityVSAvoidfile structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent leverages the existing HEIF file structure's versatility by utilizing standard box types and metadata fields that can serve multiple purposes. The encryption key is embedded using existing HEIF structures (such as iprp boxes or user data boxes) that are already part of the specification, allowing these structures to serve both their original functions and the new encryption key storage function. This reduces the increase in file structure complexity while maintaining viewing restriction capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent modifies existing HEIF file parameters and box attributes to accommodate encryption keys. Instead of creating entirely new complex structures, the invention changes the content or properties of existing boxes (such as setting specific tags, changing box types, or modifying metadata fields) to indicate the presence and location of encryption keys. This approach minimizes structural complexity changes while achieving reliable viewing restriction.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If encryption mechanisms are added to HEIF files to protect copyrights and portrait rights, then protection capability is improved, but ease of operation deteriorates (requires key management)

Engineering Contradiction:
Improveprotection capabilityVSAvoidease of operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent implements self-service encryption where the HEIF file contains all necessary encryption keys and decryption information within its own structure. The file is self-sufficient for encryption and decryption operations without requiring external key management systems or additional software components. This maintains ease of operation by allowing standard HEIF players to handle encrypted files independently, while still providing strong protection capability through embedded cryptographic controls.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent performs preliminary encryption and key embedding during the file creation or processing stage. By pre-configuring the encryption keys and viewing restrictions before the file is distributed or viewed, the system eliminates the need for complex runtime key management or user authentication procedures. This maintains ease of operation for end users while establishing strong protection capability in advance through preliminary cryptographic setup.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4050841B1File processing device and file processing method
Publication Date: 2025.04.09 SONY GROUP CORP
  • EP4050841B1 patent drawingFigure 1
  • EP4050841B1 patent drawingFigure 2~3
  • EP4050841B1 patent drawingFigure 4~6

AI summary

The present technology relates to a file processing device and a file processing method for enabling restriction of viewing of an image. A file control unit generates a file that stores an encrypted image obtained by encrypting an image with a first encryption key, and an encrypted encryption key obtained by encrypting the first encryption key with a second encryption key, the encrypted image and the encrypted encryption key being associated with each other in the file. The file control unit also decrypts the encrypted encryption key in the file into the first encryption key, and, with the first encryption key obtained by the decryption, decrypts the encrypted image into the image. The present technology can be applied to a digital camera and the like that capture images, for example.