I am looking for a RDBMS which could be embedded with an application (typically JAVA) and deployed to a client machine. The catch is I want to secure the database such that even the administrator at the client machine is unable to login or use the data files by copying them. In this case I am assuming the local Admin never knows the db password. I tried with HSQL but the first problem is it stores the db password in a plain text file.
To summarize my requirements, I need
-To be able to store data at a client machine using a JDBC 4 driver
-The data files to be only accessible by a given password which should not be stored in clear text or be retrievable to the client's administrator
-Copying the DB files to another DB instance should not work because of the password requirement
-Preferably Open Source implementation