Computing on Encrypted Data

Abstract

What if you want to query a search engine, but don’t want to tell the search engine what you are looking for? Is there a way that you can encrypt your query, such that the search engine can process your query without your decryption key, and send back an (encrypted) response that is well-formed and concise (up to some upper bound on length that you specify)? The answer is yes, if you use a “fully homomorphic” encryption scheme. As another application, you can store your encrypted data in the “cloud”, and later ask the server to retrieve only those files that contain a particular (boolean) combination of keywords, without the server being able to “see” either these keywords or your files.

We will present a recent fully homomorphic encryption scheme. In particular, we will highlight the main ideas of the construction, discuss issues concerning the scheme’s performance, and mention other applications.