DVB is the type of digital satellite data stream most receivers are able to tune in, Digicipher II being the other type. DVB is not itself encryption, but a DVB stream can be encrypted via Nagravision, PowerVu, Irdeto, etc. Our FTA receivers can tune in unencrypted DVB, but not Digicipher II (or encrypted DVB such as Nagravision, PowerVu, Irdeto, etc.)
On Lyngsat, an 'F' next to a channel on a DVB transponder means you can receive that channel. An 'F' next to a Digicipher II transponder means a channel most of us can't watch (unless you have a commercial grade DCII receiver such as the Digitrans 7150/Motorola DSR 4800)...