Encrypted Index Partial Decryption for Semantic Search
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing search systems for encrypted data in cloud services can only perform basic keyword searches and do not support advanced semantic search features, which limits the ability to consider context, location, synonyms, and natural language queries effectively.
Innovation Solution
A search system that allows for node and level-based decryption of an index structure, enabling the search of plaintext terms on a partially decrypted index, thereby supporting advanced search features like semantic searches while maintaining data privacy by only decrypting relevant parts of the index for search queries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the entire index is encrypted and stored in the cloud, then data security is improved, but advanced semantic search features cannot be performed
Solution Approach 1:
The patent divides the encrypted index into multiple encrypted shards distributed across different storage nodes. Each shard contains a portion of the encrypted search data, allowing the system to maintain full encryption while enabling search operations by processing individual shards without decrypting the entire index structure.
Solution Approach 2:
The patent introduces a trusted execution environment (TEE) as an intermediary between the encrypted index and search queries. The TEE provides a secure enclave that can perform decryption and semantic search operations in isolation, returning only search results without exposing the underlying encrypted data or index structure to external systems.
2Adaptability or versatility
If the index is partially decrypted to enable semantic search, then search functionality is improved, but data privacy is compromised
Solution Approach 1:
The patent implements partial decryption by only decrypting specific portions of the index that are relevant to the current search query, rather than decrypting the entire index. This allows semantic search functionality to operate on necessary data segments while maintaining encryption for all other portions of the index, thus balancing search capability with data privacy protection.
Solution Approach 2:
The patent applies different encryption and decryption states to different parts of the index structure based on their specific functional requirements. Critical portions that contain sensitive information remain encrypted, while portions needed for search operations are selectively decrypted, creating a heterogeneous security landscape that optimizes both privacy and functionality.
3Measurement precision
If the index is fully decrypted for search operations, then search accuracy is improved, but computational resources and time are increased
Solution Approach 1:
The patent pre-processes and organizes the encrypted index into an optimized data structure that facilitates efficient search operations without requiring full decryption. By maintaining the index in a pre-arranged encrypted format with appropriate metadata and indexing structures, the system enables accurate semantic search while avoiding the computational overhead of decrypting the entire index for each query.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A search system comprises a search server and a storage device with a file storage configured to store documents, an index storage configured to store indexes related to the documents, a document key database configured to store document keys associated to the documents in the file storage and wherein the document keys are used to encrypt and decrypt the associated document(s), an index database configured to store index keys, associated to the indexes in the index storage and wherein the index keys are used to encrypt and decrypt the associated indexes and a user key database configured to store the keys, wherein each user key is associated to a plurality of index keys and to a plurality of document keys through using the respective user key to encrypt and decrypt the associated index keys in the index database as well as the associated document keys in the document database, wherein the search server is configured to extract one or more search from a requested search query, to decrypt the accessible part of the encrypted index key with the user key which belongs to the user requesting the search query, to search the index storage based on the decrypted index keys for occurrences of the one or more terms from the requested search query, and send a search result to a terminal.