It is really hard to follow your text full of errors/typos.
Sure you can divide the public key by any number you want, but what does it help?
You can imagine the simple example of dividing by 2.
then understad how to div priv, then clone calculation to pubkey and you downgradw range from 120 to 60 bit etc
Ok. This seems to be some advanced math I do not and will not understand.
see this:
./md 91 / 8
Result: 9fffffffffffffffffffffffffffffff34ad4a102d8d642557e37b180221e8d4
xman@localhost:~/ecctools$ ./md 0x9fffffffffffffffffffffffffffffff34ad4a102d8d642557e37b180221e8d4 - 8
Result: 9fffffffffffffffffffffffffffffff34ad4a102d8d642557e37b180221e8cc
xman@localhost:~/ecctools$ ./md 0x9fffffffffffffffffffffffffffffff34ad4a102d8d642557e37b180221e8cc x 8
Result: 1b = 27 in dec
from 91 to 27
but then 2^110 to ~2^30 no result