Is there a way to encrypt a file of any type in our phone?

[ronaldwh]

Hai to all,
Is someone know how to encrypt a file, of any type, so that not every application can read/access it.
What I want to do is make another phonebook database for example 'anotherpb.cdb' or any other file, and encrypt that file, so no other application can access it.
Because if we make another phonebook database, other application can access it if it know the database's name, so I think we need to do more security act like encryption to secure that database.
So please, if there is someone who know about this, please give me some advice.
Any answer is welcome. If it can't be done, just tell me it can't be done.
Thank you so much for all of your attention !

[kkrish]

see cipher example from your sdk.