Figure 2
From: Privacy-preserving search for chemical compound databases
Schematic view of protection of (a) user privacy and (b) database privacy while keeping user privacy. For user privacy, the user's query and the search result which includes the query information must be invisible to the database side during the search task. For database privacy, the server minimizes output information for preventing regression attacks (b-1), and also detects and rejects illegal queries that might cause unexpected information leakage (b-2). These server's tasks must be carried out with the encrypted queries in order to keep user privacy.