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Procedure for finding consensus on selected numbers without sharing selection

hm flag

I was wondering if there exists an algorithm, paper, etc. for the following problem:

Assume we have a public list of numbers, let's say {1, 2, 3, 4, 5}. Alice and Bob both pick any subset of those numbers in secret. Is there a way for Alice and Bob to exchange their selections in such a way that neither Alice nor Bob know what the other person has picked, however they still see which numbers they both picked?

For instance: Alice picks {1, 2, 5} and Bob picks {2, 3, 4}. At the end Alice and Bob should know that they have {2} in common, however without knowing the other person's selection.

I don't know where to start looking for a solution.

Score:1
ru flag

The technique to which you refer is known as private set intersection.

These slides give an introduction to the problem.

This paper describes one solution using fully homomorphic encryption.

mangohost

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