We had rolled around some ideas for DRM early on, but as resources are limited (ie: we who make the firmware do so in our spare time) we had left it for 'future'.
So if you have some good re-usable ideas, let us know..
There are _many_ ways to go about doing it, but it does depend on many factors; ie if an SD is being sold, encrypting to the SD unique-id is doable, but this woudl be pretty rare by todasy standards.
Likewise, putting the suer credit card number into the pnd-file woudl prevent their wanting to share it, but woudl also be considrred rude by todays standards (yet is quite commonly done, I assure you
Ofc ourse, this does imply one faked up credit card number and repackaing the pnd woudl defeat it, so I doubt you'd go that route.
Putting some unique-id value into NAND 'somewhere' and then encrypting or testing for this value in a pnd may work, but runs victom to reflashes, or peiople runing alternate firmwares from SD; since it is botyh easy to reflash (and sometimes desirable), and relatively common for peopel to roll their own or run alternate firmware (Debian, etc), putting somethign in NAND for ID pretty inconvenient for the buyer.
For my part, I'm still a fan of the well proven 'unique ID' unlock key-code idea in sue on every phone and mobile device for 15+ years. When user buys, they provide a CC number, a name, and other values, and you hash them to make a relatively unique-id, and encrypt the pnd for the, if you so wish; or require user to enter the unlock code into the game on lauynch, to unlocjk it.. though this is a little inconvenient for the user. Buty encrypting the pnd contents (a key-file say,w ith the rest of the pnd being normal) is pretty solid. It woudl be identifiable, and the method (keygen) woudl be relatively har to reproduce (though certainly doable, of course.)
Another approach is a RSA-type key or some cvrazy hash...
If we need to extend the PXML or pnd system to support a DRM system, then we can work through it; I woudl certainly like a system that is future proof, extensible, and re-usable, so that other games could use it.
As sebt3 points out, the mailing list would be a good place to discuss it.
jeff