Data Querying Using Oblivious Pseudorandom Function Encryption
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Solution Overview
Problem
Existing data querying methods using fully homomorphic encryption algorithms are inefficient due to complex operation processes, leading to low query efficiency and security concerns.
Innovation Solution
A method and apparatus for data querying that utilize an oblivious pseudo-random function for keyword encryption, combined with a hash function and key derivation function, to decrypt ciphertext data packages efficiently and securely.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fully homomorphic encryption algorithm is used for private information retrieval, then security is improved, but operation complexity increases and query efficiency deteriorates
Solution Approach 1:
The patent segments the encryption process into two independent parts: client-side oblivious pseudo-random function encryption for keyword obfuscation, and server-side symmetric encryption for data protection. This segmentation allows each party to perform only necessary operations, reducing overall system complexity while maintaining security.
Solution Approach 2:
The patent introduces an intermediary hash function that maps keywords to fixed-length identifiers. This intermediary layer simplifies the encryption-key management process by creating a deterministic bridge between keywords and encryption keys, eliminating the need for complex key derivation operations.
2Reliability
If fully homomorphic encryption algorithm is used for private information retrieval, then security is improved, but query efficiency deteriorates
Solution Approach 1:
The patent changes the encryption parameter from fully homomorphic encryption (which requires complex arithmetic operations on encrypted data) to a combination of oblivious pseudo-random function encryption and symmetric encryption. This parameter change maintains security while dramatically improving query efficiency by using simpler encryption operations.
Solution Approach 2:
The patent performs preliminary encryption of keywords using the oblivious pseudo-random function before the actual data retrieval. This preliminary action obfuscates the query intent without requiring complex homomorphic operations during the data fetching process, thereby improving overall query efficiency.
3Productivity
If simple encryption functions are used for data querying, then query efficiency is improved, but security deteriorates
Solution Approach 1:
The patent uses a composite encryption approach combining multiple encryption functions: oblivious pseudo-random function for keyword obfuscation, hash function for deterministic mapping, and symmetric encryption for data protection. This composite approach maintains high security while achieving good query efficiency through optimized operation flow.
Solution Approach 2:
The patent creates a deterministic copy of the keyword through the hash function, which serves as a reliable identifier for retrieving encrypted data. This copying mechanism ensures security by maintaining keyword privacy while enabling efficient data location and retrieval through the hashed identifier.
Data Source
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AI summary
Provided in the present disclosure are a data query method and apparatus, a device and a medium. The method comprises: acquiring a first keyword to be queried; on the basis of an oblivious pseudorandom function, encrypting the first keyword to obtain a first oblivious pseudorandom function value corresponding to the first keyword; determining a first hash value of the first keyword on the basis of the first oblivious pseudorandom function value and a hash function, and determining a first key of the first keyword on the basis of a key derivation function; and, on the basis of the first hash value, the first key and a symmetric encryption algorithm, decrypting a ciphertext data packet provided by a server to obtain a query result corresponding to a data query operation. The present disclosure helps to improve the efficiency of data query.