Unfortunately, I've found that the encryption setting isn't exposed programmatically, although I haven't investigated DXL or the database design class available on the LDD sandbox for references. Nonetheless, you may not need to set it. Starting in Lotus Notes Domino R6, local replica copies receive medium-level encryption settings by default. If this suits your needs, you can create the replica:
Dim Session s = new NotesSession
Dim replicaCopy as NotesDatabase
Set replicaCopy =
s.currentDatabase.CreateReplica("","filename.nsf")
Do you have comments on this Ask the Expert Q&A? Let us know.
Related information from SearchDomino.com:
This was first published in February 2008