Secure and efficient approximate nearest neighbors search

This paper presents a moderately secure but very efficient approximate nearest neighbors search. After detailing the threats pertaining to the `honest but curious' model, our approach starts from a state-of-the-art algorithm in the domain of approximate nearest neighbors search. We gradually develop mechanisms partially blocking the attacks threatening the original algorithm. The loss of performances compared to the original algorithm is mainly an overhead of a constant computation time and communication payload which are independent of the size of the database.