METHOD OF CONFIDENTIAL INTERROGATION OF A GEODEPENDANT SERVICE BY HOMOMORPHIC CRYPTOGRAPHY

摘要

A method allowing a user confidentially to query a server including a database. The user builds, from an index of a desired entry, a vector encrypted by a homomorphic probabilistic cryptosystem, and transmits a request having the vector as an argument to the server. The server performs a scalar product between the vector of entries of the database and returns the result to the user. The user decrypts the scalar product to obtain the desired entry. The method can be used for example for querying a location-based service and for navigation by concealed routes.