From ActiveCrypt Software:
DbDefence Database Encryptor is a network defense program designed to protect the valuable data housed within your server's network-dependent SQL database. DbDefence Database Encryptor transparently encrypts any database without modifying the surrounding server applications. The program prevents access to the database tables entirely until a very specific SQL statement and password created by the software is entered into the system. Each application, which wants to access the SQL database, must execute this very special statement with the correct password attached in order for the encrypted SQL database to be read or accessed by any other applications. This gives network administrators complete control over how access is gained into the SQL database.