scrambled data / security

Howdy:

Running Postgres 7.1.3 on RedHat Linux 7.2.

Question about security.  I have data that I want to
present, except that the information is really
sensitive.

I know there is a way to scramble the data so
that it appears garbled.  How can I do that?
Where can I get find documents on that?  (I'm
looking in the PostgreSQL book and might
be missing it).

Thanks!

-X