Re: potential break or real break?



OTP is not vulnerable because the key (not the keystream) is as long
as the plaintext so a brute force attack just produces all possible
plaintexts with that length, from "aaa ... aaa" to "zzz ... zzz", with
no way for the attacker to tell which message is the correct one.

rossum

If the file is an image for example, or anything other than a plaintext
file, a .doc for example, regardless of if it's an OTP or a keystream then a
brute force has to try every possible key stream anyway because there is no
way to know if it is correct or even partially correct unless it is fully
and correctly decoded. a jpeg for example may decode to the correct size,
but if even one byte in the file is corrupted the jpeg will either not load,
or will be corrupted on some level or other. this could be as little as 1
pixel or as much as half the image. the decode of any file can be monitored,
a plaintext file is easy to monitor to see if it is being decoded correctly,
an image is not. numerous times have i encoded something and then run the
decode only to have it register as the particular file type that it was
before encoding, a bitmap for example, but when you try to open it, it comes
up as an error, or thing's don't look right.


.



Relevant Pages

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