DotProduct
Newcomer
Unless I'm misunderstanding you in what you mean by having the key built into the gates.
What I mean is that in every consumer Cell there is one RSA/IDEA DSP, decrypting every opcode. There is ONE single RSA public key hardwired into every consumer Cell.
Sony (and only Sony) has the according private key.
That way every piece of code has to be signed by Sony.
I am no hardware guy, but I am pretty sure that there would no cheap way to alter the RSA public key to run you own code.
The principle would be the same as with current XBox, but with code and encryption hardwired into the cpu.