Searchable Encryption Indexing for Encrypted Data Processing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional searchable encryption systems face significant performance issues when dealing with large volumes of encrypted data, requiring numerous searches to be performed sequentially, which results in impractically long processing times as the number of data pieces increases.

Innovation Solution

The system employs a searchable encryption processing method that uses a management server to store secret data and secret indices, allowing for encrypted queries to be processed efficiently by utilizing homomorphic functions, compression, and XOR operations to reduce the search complexity and speed up the query process without decrypting the data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional searchable encryption methods are used to maintain security of encrypted data, then data security is improved, but search processing time increases exponentially with data volume

Engineering Contradiction:
Improvedata securityVSAvoidsearch processing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent divides the encrypted search space into multiple segments or partitions. Instead of performing exhaustive search across all encrypted data, the system segments the data storage structure and applies targeted search operations to relevant segments only, significantly reducing the number of search operations required while maintaining security.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary processing to create encrypted indexes or metadata structures that enable faster search operations. By pre-organizing encrypted data with searchable properties before actual search queries, the system reduces the computational burden during actual search operations without compromising data security.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If exhaustive search is performed on all encrypted data to ensure complete search coverage, then search completeness is improved, but processing speed deteriorates

Engineering Contradiction:
Improvesearch completenessVSAvoidsearch processing speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent introduces encrypted indexes or intermediate data structures that act as mediators between the search query and the encrypted data storage. These intermediaries enable the system to achieve complete search coverage without examining every piece of encrypted data directly, thus maintaining search completeness while improving processing speed.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If probabilistic encryption is used to prevent information leakage, then data confidentiality is improved, but search operation complexity increases

Engineering Contradiction:
Improvedata confidentialityVSAvoidsearch operation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent modifies encryption parameters or adopts specific encryption schemes that balance confidentiality with searchability. By carefully selecting encryption parameters and structures, the system maintains strong data confidentiality while enabling efficient search operations without excessive complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3096245B1Retrievable cryptograph processing system and retrievable cryptograph processing method
Publication Date: 2020.12.02 HITACHI LTD
  • EP3096245B1 patent drawingFigure 1
  • EP3096245B1 patent drawingFigure 2
  • EP3096245B1 patent drawingFigure 3

AI summary

A searchable encryption processing system includes a server including: a communication device to communicate with another device; a storage device configured to store as search target data, secret data obtained by concealing plaintext data, and a secret index obtained by concealing a plaintext index to classify the plaintext data; and an arithmetic device to execute a process including receiving, from a search client, a secret data query obtained by concealing a plaintext query, and a secret index query obtained by concealing a plaintext index, searching the storage device for a secret index matching the secret index query based on a predetermined searchable encryption technique, searching a secret data group classified by the matching secret index for secret data matching the secret data query, and returning the searched secret data to the search client.