There's an Encryption software included in the package, but it's not necessary. I tried it and it worked well at first. But somewhere down the line, the adapters stopped recognizing each other. So, I uninstalled the Encryption tools and it worked fine since then.
I've used the XE602's to connect two Xbox's located in two separate rooms to play System Linked games. It's much easier than getting two large TV's into one room. Ever played Halo with 8 players? Now you can without cramming 8 screaming people into one room.
The XE602's also work well with broadband Internet gaming. Whenever we had guests, I would move the Playstation 2 and an XE602 downstairs and let them play Socom Navy Seals online. When they left, I simply packed everything up and moved them back upstairs. Quick and easy.
The only negative (and this applies to all the current powerline networking items) is they need to plug right into the wall. Given how many plugs a desktop computer needs you will need a surge protector with LOTS of plugs to free up a wall socket.
Also, one word of advice, keep this in a reasonably well ventilated area. I had mine partially covered and it got too hot and stopped working. After I uncovered it and let it cool down for a few minutes it started working again.