Invisible <voi### [at] devnull> wrote:
> All I *really* want to know is the probability of a random alteration to 
> a file going undetected by an MD5 hash comparison.

  I think it's quite unlikely.

  I wonder how much more unlikely it would be if you calculated two MD5
codes: The first one is calculated in the regular way, and the second one
is calculated starting from the second byte in the file forwards, and taking
the first byte as if it was the last (iow. effectively as if you had removed
the first byte of the file and appended it to the end of the file).

  A random change which would keep one of the MD5 sums the same would
quite unlikely keep the other one the same too. I have no idea about the
probabilities, though.

-- 
                                                          - Warp

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