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Re: xor data hiding?
According to Douglas Sinclair:
>
> What you are talking about sounds like the original Vernam cipher that Dave
> Kahn talks about in _CodeBreakers_. There, he was using a teletype with two
> XORing tapes. One tape was 1000 characters long, the other was 999. Thus,
> 999000 characters would have to go past before the system repeated. HOWEVER,
> once it does repeat, all security is compromized. Even before that time,
> I believe there are subtle attacks you can use based on the repetition of the
> keys. So, this is not a secure cipher method. I would personally
> suggest tacking an 128 bit IDEA key onto 4dos.com instead. Or use
> DES even.
The point wasn't to be unbreakably secure; it was to be UNFINDABLY secure. We
convolute an allready encrypted message to the point of not being recognizable
as cyphertext, then we hide it on the end of a file. We want it to look like
garbage.
> BTW: Though you could come up with a 30Kb+ string which when XORed would
> give you any plaintext, you could not come up with a few small strings
> which when used over each other would give you that. There just isn't enough
> information to make that possible.
Agreed. This leaves us with several OTP's laying around in zip format. This
isn't so bad as long as we don't forget the original 7 keys. The main purpose
of all of this is plausible deniability.
Thanx for your comments. Still listening.
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