The Maverick APIs will use your System's preferred JCE provider. It is possible to override this by calling a few methods on the JCEComponentManager.
You can initialize a default provider to use for all algorithms using:
Alternatively if you need to use a specific Provider for a specific Algorithm you can set this using
JCEComponentManager.initializeProviderForAlgorithm(JCEAlgorithms.JCE_AESCTRNOPADDING, new BouncyCastleProvider());
If you are using our 1.4 server API then you need to use JCEServerComponentManager in the above examples. The 1.4 client and 1.6 client and server APIs share JCEComponentManager.