I really need your help guys. I browse, search around the forums, on google, yup, there are many tutorials on it , but since i'm a newbie, i just can't understand how it's works, could you guys post a working example on it. I thanks.
here's the value of the key:

39,ff,0d,d8,7c,74,a4,7f,73,99,b8,cb,ba,3d,b1,44,c9,71,\
63,4c,ca,fe,2f,cc
.... and so on