u/EducationalTackle819

I work with a company that sells data. As an example, let’s say we are selling email addresses. A frequent request we’ll get is, “We’ll we already have a lot of emails, we only want to purchase ones you have that we don’t”.

We need a way that we can figure out what data we have that they don’t, without us giving them all our data or them giving us all their data.

This is a classic case of private set intersection but I cannot find an easy to use solution that isn’t insanely expensive.

Usually we’re dealing with small counts, like 30k-100k. We usually just have to resort to the company agreeing to send us hashed versions of their data and hope we don’t brute force it. This is obviously unsafe. What do you guys do?