Encrypted Data Block Comparison via Shuffling and Magnitude Embedding
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Solution Overview
Problem
Existing data comparison technologies that compare encrypted data risk unauthorized decryption due to potential information leakage from similarity determinations in magnitude comparisons between encrypted values.
Innovation Solution
A data comparison device and method that encrypts data into blocks, shuffles these blocks, and embeds a value indicating the magnitude comparison result, allowing secure comparison without revealing the original data similarity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If encrypted data is compared using magnitude comparison, then comparison function is achieved, but information leakage occurs revealing similarity between encrypted data and original values
Solution Approach 1:
The encrypted data is divided into multiple blocks, and comparison is performed block by block from most significant to least significant. This segmentation allows the system to determine magnitude relationships without revealing the complete encrypted value, as only partial block comparisons are needed to establish the result.
Solution Approach 2:
The system performs preliminary comparison actions on individual blocks before determining the final magnitude relationship. By comparing blocks sequentially and stopping when the relationship is determined, the system avoids unnecessary information leakage about less significant blocks that would not affect the final comparison result.
2Reliability
If encrypted data is compared without decryption, then data secrecy is maintained, but unauthorized decryption risk increases due to similarity analysis
Solution Approach 1:
The system transforms the comparison problem from operating on complete encrypted values to operating on individual blocks of encrypted data. This dimensional change allows comparison functionality while limiting the information available for similarity analysis, as attackers can only observe block-level comparison results rather than relationships between complete encrypted values.
3Measurement precision
If complete encrypted values are compared, then accurate magnitude comparison is achieved, but more information about encrypted data similarity is revealed
Solution Approach 1:
The system performs preliminary comparisons on more significant blocks first and stops the comparison process as soon as the magnitude relationship is determined. This means less significant blocks are not compared at all in many cases, providing accurate magnitude comparison while minimizing the amount of information leaked about data similarity.
Data Source
AI summary
A data comparison device holds first and second encrypted data of first and second plaintext, respectively. The first plaintext is divided into a plurality of blocks and the first encrypted data is generated by executing encryption of each of the plurality of blocks and shuffling of the plurality of blocks. The second plaintext is divided into a plurality of blocks and the second encrypted data is generated by executing encryption of each of the plurality of blocks. In at least one of the first encrypted data and the second encrypted data, a plaintext value is embedded as a value indicating a magnitude comparison result, and the data comparison device compares blocks at the same position before shuffling of the first encrypted data and the second encrypted data based on the embedded value and determines a magnitude relationship between the first plaintext and the second plaintext.