Secure Equijoin System Using Permutation and Prefix Sum
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Solution Overview
Problem
Existing equijoin techniques in secure computation require significant communication traffic, especially when the number of overlapping key attribute values is large, leading to inefficiencies in database processing.
Innovation Solution
A secure equijoin system that uses a permutation-based approach to reduce communication traffic by generating a table with fewer columns and rows, leveraging stable sort, permutation, and prefix sum computations to minimize data transmission, specifically optimizing the process for tables with overlapping key attributes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional equijoin techniques are used in secure computation, then the equijoin operation can be performed, but the communication traffic becomes excessively large, especially when the number of overlapping key attribute values is large
Solution Approach 1:
The patent segments the equijoin process into multiple phases: sorting phase, permutation phase, and join phase. Each phase processes data in a controlled manner, with only necessary data being transmitted between parties. The sorting and permutation operations are performed locally, reducing the amount of data that needs to be communicated during the actual join operation.
Solution Approach 2:
The patent performs preliminary sorting and permutation operations on the input tables before the actual equijoin. By pre-sorting the tables based on key attributes and generating permutations, the system prepares the data in advance so that the subsequent join operation requires minimal communication. This preliminary processing reduces the communication burden during the critical join phase.
2Reliability
If the number of secure computation devices is increased to improve reliability, then the security and reliability of the computation is improved, but the communication overhead and system complexity increase
Solution Approach 1:
The patent designs the secure equijoin protocol to work effectively with a small number of secure computation devices (typically 3 devices), making the system universally applicable without requiring a large number of participants. The same protocol structure can be executed with minimal devices, reducing system complexity while maintaining security and reliability through the multi-party computation framework.
Data Source
AI summary
A secure equijoin technique of generating one table from two tables while curbing the volume of communications traffic is provided. The technique includes: a first permutation generating means 110 that generates a permutation <σ> from an element sequence which is generated from the first column of a table L and the first column of a table R; a first column generating means 120 that generates, for j=2, . . . , a, by using the permutation <σ>, a prefix sum, and an inverse permutation <σ−1>, the j-th column of a table J from an element sequence which is generated from the to j-th column of the table L; a join-result element sequence generating means 130 that generates a join-result element sequence from an element sequence ([[1]], . . . , [[1]], [[0]], . . . , [[0]], [[−1]], . . . , [[−1]]) by using the permutation <σ>, the prefix sum, and the inverse permutation <σ−1>; a second column generating means 140 that generates, for j=a+1, . . . , a+b−1, the j-th column of the table J by using the join-result element sequence and the j−a+1-th column of the table R; and a third column generating means 150 that generates the first column of the table J by using the join-result element sequence and the first column of the table R.