The encryption is totally automatic you don't need to do anything the only thing you will be interested in on the receiver is the serial output which gives the transmitters serial number and which button was pushed.
The reason I picked this set-up was because it was cheap £15 for the receiver and £14 for the 3 button remote, the remote's with less buttons were cheaper (£10 I think for a 1 button)
I had a quick look at the receiver's on the Linx website that was linked ..correct me if I'm wrong but if you use those receivers you set the channel by DIP switches or hard-wiring the channel in, so you would need a receiver for every remote ?
zx