system key different in 'new' digital?

[radio64]

Hi All-

I have not had a need to program any of the new digital radios yet, but that time might be coming up quickly... Was wondering if the system key for trunked systems is an entirely different key from the 'analog' to the 'digital' systems? As an example, I've got a BB37 key for an analog user, and see a 1D6 for a different (upgraded) system. Is it as simple as creating that key, or is there an entirely new structure? Thanks.