in reply to Re^3: Calculating corruption
in thread Calculating corruption

but storing a checksum of the encrypted file will be useless wouldnt it? because i am not sure if even the first file will be corrupted. i wouldnt want to generate a hash for a corrupted file to check with. i need to check the first original file for corruption. and like i say, the file cannot be decrypted because the keys to decrypt it are unknown afaik :l

the next idea i had would be checking it for randomness. an excrypted files should be very low or null on repeating byte characters, shouldnt it? but how do you check a file for byte character randomness, or randomess at all? <.<

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Re^5: Calculating corruption
by Jim (Curate) on Oct 18, 2014 at 23:42 UTC

    There's no solution to the problem you've described. And I don't loosely mean there's no tractable solution to the problem; I mean there's utterly no solution at all.

    UPDATE:  I just realized someone else has already made this same point elsewhere in the thread.

Re^5: Calculating corruption
by LanX (Saint) on Oct 19, 2014 at 11:03 UTC
    If you can't checksum the file right after encryption then better try Dowsing !

    Anyway I expect most encryption methods to detect corruptions by themselves, hence a pretty fruitless discussion.

    Cheers Rolf

    (addicted to the Perl Programming Language and ☆☆☆☆ :)

    PS: Talking about statistics, ignoring users with many trailing digits proofs to be an excellent rule of thumb to avoid "corrupted" (and cryptic) questions.

    Thanks! :)

      the best thing i can do is provide proofs to what i am saying. tomorrow i will compile a list of outcomes on these files. :) and you can judge for yourself