By default PostgreSQL will store data on disk in its standard format. However, in many cases business or legal requirements require data to on disk be encrypted. On disk-encryption was paid for by German industry and is a classical case showing how business and Open Source can coexist. This talk shows, that it can be actually cheaper to implement a feature into an Open Source product than to license a commercial product such as Oracle, DB2, Informix, or MS SQL Server. Open Source can make a valuable contribution to save costs for everybody.