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A Modernised One –Time Pad is Quite Feasible.

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adacrypt

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Feb 13, 2012, 12:22:02 AM2/13/12
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A modernised OTP that does not have the historic key transport
problem, has a manageable message/key length, has ciphertext that is
demonstrably random, does not show footprints in the ciphertext even
if the key is used more than once (which it isn’t but could be made to
do so – has been checked), has an acceptable message length, is
demonstrably strong enough under all traditional attacks - not a bad
days work!

That is what I have always contended I have - I reckon its here to
stay after all, despite the howls of *fearful protest.

Come to think of it all future ciphers may well be otp’s in any case
without the anachronistic one-time-ness – this will happen naturally
so why keep up the cant.

- adacrypt

Mark Murray

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Feb 13, 2012, 2:17:31 AM2/13/12
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On 13/02/2012 05:22, adacrypt wrote:
> A modernised OTP that does not have the historic key transport
> problem, has a manageable message/key length, has ciphertext that is
> demonstrably random, does not show footprints in the ciphertext even
> if the key is used more than once (which it isn’t but could be made to
> do so – has been checked), has an acceptable message length, is
> demonstrably strong enough under all traditional attacks - not a bad
> days work!

If your talking about the hard-coded-constants stuff that you already
have, then you are patently wrong.

> That is what I have always contended I have - I reckon its here to
> stay after all, despite the howls of *fearful protest.

We all know hat you think you have. What you don't know is that its
not a failure to understand, its a failure to agree.

Your naive attempt to poison the well with "fearful protest" holds
no water.

> Come to think of it all future ciphers may well be otp’s in any case
> without the anachronistic one-time-ness – this will happen naturally
> so why keep up the cant.

Look up wht the bloody term means!

"One Time Pad" means "use the keys once". Does yours recycle the key
material?

YES.

ITS NOT A ONE TIME PAD!

Time for more "lalalalalalalala" and a new thread?

M
--
Mark "No Nickname" Murray
Notable nebbish, extreme generalist.

Bruce Stephens

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Feb 13, 2012, 5:13:32 AM2/13/12
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adacrypt <austin...@hotmail.com> writes:

> A modernised OTP that does not have the historic key transport
> problem, has a manageable message/key length,

You can't have that if you want the OTP security guarantees. OTP
requires that the key space be at least as large as the plaintext:
that's what provides the security guarantee.

[...]

adacrypt

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Feb 13, 2012, 5:43:24 AM2/13/12
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On Feb 13, 10:13 am, Bruce Stephens <bruce
+use...@cenderis.demon.co.uk> wrote:
It would be truer to say that the OTP requires a 'random' keyset that
is constrained to being the same length as the message length - an
affliction rather than a blessing - this was the first use of
randomness in cryptography.

The operative word is hugely random.

- adacrypt

Mark Murray

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Feb 13, 2012, 1:45:43 PM2/13/12
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On 13/02/2012 10:43, adacrypt wrote:
> It would be truer to say that the OTP requires a 'random' keyset that
> is constrained to being the same length as the message length - an
> affliction rather than a blessing - this was the first use of
> randomness in cryptography.

Right up to "... message lenth", you are doing fine. After that,
you display the usual startling ignorance.

> The operative word is hugely random.

I can't figure out what the hell you mean by this, but given
your usual wrong rambling about random numbers, I'm assuming
that you are typing much faster than you are thinking.

Bruce Stephens

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Feb 13, 2012, 2:15:31 PM2/13/12
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adacrypt <austin...@hotmail.com> writes:

> On Feb 13, 10:13 am, Bruce Stephens <bruce
> +use...@cenderis.demon.co.uk> wrote:

[...]

>> You can't have that if you want the OTP security guarantees. OTP
>> requires that the key space be at least as large as the plaintext:
>> that's what provides the security guarantee.
>
> It would be truer to say that the OTP requires a 'random' keyset that
> is constrained to being the same length as the message length - an
> affliction rather than a blessing - this was the first use of
> randomness in cryptography.

You're jumping over the argument.

OTP provides the following security property: if an attacker can see (by
ciphertext length, say) that there are P possible plaintexts, the
ciphertext gives no information about which plaintext of the P is
correct.

That requires that the number of possible keys be at least P. If it was
P-1, then an attacker (one with unlimited resources) can try all P-1
keys producing (presumably) P-1 plaintexts and then know a plaintext
that's impossible. (Admittedly that's probably not useful information
about the plaintext, and anyway the keyspace is probably large enough to
make doing this impossible in just our universe, but those are true of
known attacks against other systems, too.)

[...]

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