Abstract
Suppose that persons A and B give us a sequence of 32 bits each, saying that they were obtained from independent coin flips. If A gives the stringu = 01001110100111101001101001110101and B gives the stringv = 00000000000000000000000000000000,then we would tend to believe A and would not believe B: the string u seems to be random, but the string v does not. Further on, if we change the value of a bit in a “random” string, then the result is still a “random” string. If we keep making such changes in a “random” string, then we will eventually complete destroy randomness