The 20 Digit NCK Newer Phones r now In market
Cannot be Calculated with BF servers or Local BF for Unlocking
The current way to find out about newer Phone either it uses the 15 digit or 20 digit NCK ..
The easiest way is just to check the Length of PM 120,2.

134 = SL3 20-digit NCK
130 = SL3 15-digit NCK
120 = PA_SL2

is the current method being used ..