Re:Have I Been Facebooked?
by CloselyChunky on Tuesday April 06, 2021 @10:19AM
(#26712053)
I think HIBP implements it like this: you hash your email/phone number and send only a prefix of the hash to the server. The server responds with a list of hashes matching the prefix. Now you can check if your hash is in the list. If so, you have been pwned. This way the server never knows which email you are requesting since it only ever sees a part of the hash.
(Assuming seeing hacked numbers are public already - but I don’t love this either)
What’s a secure way of searching without disclosure by either party? (Non troll question)