Private Set Intersection via Blockchain and Secret Sharing
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Solution Overview
Problem
Existing private set intersection solutions in smart city systems face challenges such as uneven set sizes, storage issues, and inefficiencies due to the single-set nature of current solutions.
Innovation Solution
A method utilizing a third-party generated hash function and public keys for encryption, combined with blockchain verification and secret sharing technology, to enable secure and efficient private set intersection between participants in a smart city system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current private set intersection solution is used, then privacy of set elements is ensured, but set sizes must be uniform which limits practical application
Solution Approach 1:
The patent divides a single large set into multiple smaller subsets. Each participant partitions their set S into subsets S1, S2, ..., Sn where each subset can be processed independently. This segmentation allows participants with different total set sizes to perform intersection operations on corresponding subsets without requiring uniform overall set sizes, while still maintaining privacy through the same cryptographic protocols.
2Device complexity
If single-set structure is used, then implementation is simple, but storage and efficiency problems occur
Solution Approach 1:
By dividing large sets into smaller subsets, the patent reduces the computational burden on each intersection operation. Smaller subsets mean fewer elements to process, encrypt, and compare, directly improving intersection efficiency and reducing storage requirements for intermediate data structures while maintaining the overall system framework.
Solution Approach 2:
The patent introduces dynamic selection of subsets for intersection based on participant needs and data distribution. Participants can dynamically choose which subsets to intersect rather than being forced to process entire sets, allowing flexible optimization of computational resources and improving overall system productivity adaptively.
3Ease of operation
If uniform set size is enforced, then protocol simplicity is maintained, but real-life skewed set sizes cannot be handled
Solution Approach 1:
The subset partitioning approach allows the protocol to handle skewed set sizes by processing only corresponding subsets. If participant A has set size 1000 and participant B has set size 500, both can be divided into subsets of size 500, allowing the intersection protocol to run on matching subsets while preserving protocol simplicity and achieving real-life compatibility.
Data Source
AI summary
The present invention discloses a method for private set intersection in a smart city system, a device, and a storage medium. According to the present invention, a threshold secret sharing technology is adopted to share a private set among three parties, so that an intersection cardinality is hidden and security of private set intersection is improved. Before two parties perform the private set intersection, a blockchain is used to verify identities of the two parties, which protects security of data of the two parties to a certain extent. In addition, according to the present invention, the private set is divided into a plurality of subsets with labels, which implements an interaction manner with finer granularity. Therefore, compared with a private set intersection solution in a previous smart city system, the present invention is greatly improved in practicability, security, and other aspects.