Cryptographic Search Index for Encrypted Digital Documents

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for searching secure and encrypted digital documents face challenges in maintaining security while allowing effective searches, as accessing encrypted documents for search terms can compromise data integrity.

Innovation Solution

A method that applies a cryptographic function to individual elements of digital works to create a searchable index, allowing for secure searching without decrypting the original content, by converting elements into unreadable patterns for comparison with search terms, thereby maintaining confidentiality and reducing computational resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If encrypted documents are accessed for searching, then search functionality is enabled, but data security is compromised

Engineering Contradiction:
Improvesearch functionalityVSAvoiddata security
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The document is segmented into individual elements (words, phrases, or other units), and a cryptographic function is applied to each element separately to generate corresponding index elements. This allows the index to be searched without requiring decryption of the entire document, thus enabling search functionality while maintaining data security.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the parameter of the document from plaintext to encrypted form by applying a cryptographic function to generate index elements. This transformation allows the index to be searchable while the original document remains encrypted, resolving the contradiction between searchability and security.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If entire documents are scanned for search terms, then comprehensive search results are obtained, but computational time and resources increase

Engineering Contradiction:
Improvesearch completenessVSAvoidcomputational time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

An index is pre-generated by applying the cryptographic function to individual elements of the document before the search operation. This preliminary action creates a structured representation that can be quickly searched, avoiding the need to scan the entire document during the search process and thus reducing computational time while maintaining search completeness.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If security measures are applied to protect sensitive documents, then data confidentiality is maintained, but search effectiveness is reduced

Engineering Contradiction:
Improvedata confidentialityVSAvoidsearch effectiveness
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent introduces an intermediary index structure that is generated from the encrypted document through application of a cryptographic function. This intermediary serves as a bridge between the encrypted document and the search function, allowing effective searching without compromising the confidentiality of the original document.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2729882B1Search index
Publication Date: 2020.02.19 BUSINESS PARTNERS LTD
  • EP2729882B1 patent drawingFigure 1
  • EP2729882B1 patent drawingFigure 2
  • EP2729882B1 patent drawingFigure 3

AI summary

Method of searching comprising applying a function to individual elements within a digital work to form a set of index elements. Storing the index elements as an index for the digital work. Receiving a search term. Applying the function to one or more individual elements within the search term to convert the search term into one or more converted search term elements. Identifying a digital work having an index containing one or more index elements that match one or more of the converted search term elements. Returning search results of the identified digital work. Searchable index for a digital work formed by applying a function to individual elements within the digital work to form a set of index elements.