Advice needed on using postgres in commercial product

Hi all,

We're currently developing some large-scale software with the intention
of selling it (online and off-the-shelf). The version in development uses
Postgres to store stuff in a number of large databases.

Ignoring potential licensing issues for now, the big issue for us is that
the data in the databases has significant intellectual property value. It
has taken literally years of work to collect the data. We do not want the
users of the commercial product to be able to fire up postgres and type
something like: user]% pg_dump their_data > our_product

Additionally, we don't want to have to encrypt every entry in the database,
because that will cause significant overhead during processing.

My question is, what options do we have? Can postgres store data as some
sort of unreadable binary, much like you would find in a C binary data file?

If not postgres, what other database could possibly do this, if any? I
really don't want to have to write our own RDBMS. :)

Thanks in advance for any advice or suggestions on this subject,

Pakt.