How Is The Cpu Key Generated? Options

[paulmedynski]

Hey folks,

Does anyone have complete details on how the CPU key is generated at manufacture time? I'm interested in knowing what the inputs are and how they end up forming the key. I'm finding it difficult to find anything relevant via Google.

Thanks,
-Paul

[Juvenal1228]

again, no one knows for sure, but to the best of my knowledge, and if you have ever had a JTAG you gather this info.

1. CPU key and serial #/console ID are not tied to each other, as you can swap the serial and such for xbl unban
2. CPU key is stored in the fuses on the CPU, on line 3/4 and 5/6
3. line 3 & 5 are the first half (they are duplicates) and line 4 & 6 are the second half (again, dubs of eachother)
4. Other lines of eFuses are used for blacklisting old bootloaders and kernels I.E. a new fuse is burned after some updates to prevent booting older (possibly insecure) kernels/bootloaders I.E. when they blocked the JTAG hack


My guess is the CPU key is indeed random, or as random as a computed event can be.