There's numerous posts about reading the Pi's serial number from /proc/cpuinfo. I'm considering using the serial number as a unique id for licencing commercial software but am concercned that /proc/cpuinfo could possibly be faked (I stumbled on a few links that suggested it was easily possible but I haven't verified them: https://www.raspberrypi.org/forums/viewtopic.php?p=541842#p541842, Editing Serial Number etc.).
I also verify that /proc/cpuinfo reports a size of zero, but I'm not sure if that can also be worked around.
Is there a way to programmatically read the serial directly from the broadcom chip?