Derby supports disk encryption, but you must supply the following:
Derby does not support earlier, non-exportable, versions of JCE (such as JCE 1.2). More information on JCE 1.2.1, including a product download, can be found at: http://java.sun.com/products/jce/index.html.
Any attempt to create or access an encrypted database without the libraries for an implementation of JCE of the proper version, or without Java 2 Platform, Standard Edition, v 1.2 (J2SE) or higher, raises an exception; you will not be able to create or boot the database.
An encryption provider implements the Java cryptography concepts. The JRE for J2SE 1.4 or J2EE 1.4 includes JCE and one or more default encryption providers.