Via Diehard test:
"C:\Program files\ENT>ent xored.bin
Entropy = 8.000000 bits per byte.
Optimum compression would reduce the size
of this 410820608 byte file by 0 percent.
Chi square distribution for 410820608 samples is 243.08, and randomly
would exceed this value 50.00 percent of the times.
Arithmetic mean value of data bytes is 127.5014 (127.5 = random).
Monte Carlo value for Pi is 3.141694679 (error 0.00 percent).
Serial correlation coefficient is -0.000020 (totally uncorrelated = 0.0).