How do I make a "security environment"?

Question

I need to do something I don't even know if is possible..

We have a code that handle crypted data, and we have another software that is open source and need to manipulate this data, both are desktop stand alone softwares.

I'm wondering, is there a way to create a "secure environment" in Java to use the open source software as a plugin, restricting this software's access do external world (I don't want it to externalize my decrypted data)?

Any help would be appreciated.

Answer 1

I don't know the details, but a Security Manager is intended for that purpose, also a custom ClassLoader might prevent loading of resources you don't want to get loaded.