Comment by cromwellian
12 years ago
You don't need full homomorphic encryption to do encrypted search, look up PKES systems, there's tons of papers on it now (http://crypto.stanford.edu/~dabo/abstracts/encsearch.html). It's possible to encrypted keyword search with trapdoor functions in such a way that the server can't learn anything about what you're searching on, nor what is stored.
Are you aware of any vaguely practical systems for a variant of keyword search that just returns whether the keyword was found (e.g. 1 for found, 0 for not found) but with the added requirement that the result must itself be encrypted? I suspect it degenerates to fully homomorphic encryption though.
By result itself, you mean the boolean 1/0 about whether it was found? Yes, I am aware of one I saw some time ago that had additional guarantees, I don't know how practical it was though, but it'll take some searching to find.