It's FHE applied to solve a variant of oblivious transfer, called "private information retrieval" (https://en.wikipedia.org/wiki/Private_information_retrieval). PIR is very similar to oblivious transfer, except that in oblivious transfer, the privacy is mutual - the client learns exactly one element from the database; in PIR, it's ok if the client learns some number of 'extra' items other than the one it queried.
blintz|3 years ago