I am facing a 64-bit secure key, it seems too hard by just simply searching the whole key space
A general estimation - if a machine has the power to compare the lower 32-bit part per second, the higher 32-bit part cycle would cost near 140 years
If there are 140 or more such powerful boxes, the task may be done in a year, with proper task schedule, etc ...
I am wondering if there is anybody willing to help.