How can I compare two (email) lists without viewing the content

Andy July 3, 2011
Pinterest Stumbleupon Whatsapp

I need to compare an email list with a list curated by someone else and see the % of overlap.

The first thought is to make hashes out of each email. However this only works until a match is found. Once we have overlap we will both know who is a double-subscriber, and this is arguably confidential info.

Any idea how to do this.

Is there any service that would allow us to compare? I am thinking that the matches would be meaningless for that 3rd party.

Ads by Google