Kjazlaw, keebeen, amb#cog, just ask us for info if you want. some people just.
RC5 is just a cracking challenge. I personally don't know too much about how exactly we win (you find the block with the code? something like that.
but anyway, all you do is run this little program, and it sits there and takes the CPU time that you are not using (no lie, it really does this, you don't notice it AT ALL) to work on units that it downloads. simple as that.