If your cipher were secure, this image wouldn't have obvious repeating patterns

Re: [Cfrg] Crystalline Cipher

Tony Arcieri <bascule@gmail.com> Thu, 21 May 2015 00:35 UTC

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From: Tony Arcieri <bascule@gmail.com>

Date: Wed, 20 May 2015 17:34:45 -0700

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To: Mark McCarron <mark.mccarron@eclipso.eu>

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Subject: Re: [Cfrg] Crystalline Cipher

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On Wed, May 20, 2015 at 3:59 PM, Mark McCarron <a href="mailto:<mark.mccarron@eclipso.eu>"><mark.mccarron@eclipso.eu></a>
wrote:

> I'm somewhat disappointed in your reply, as I presumed that someone with a
> stated interest in ciphers would be eager to investigate anything new to
> pop up that didn't have obvious holes in it.


Hi Mark,

I did investigate your scheme, and I'm afraid to say it's obviously broken.
It appears to be an implementation of a Knuth Shuffle with a few added
bells and whistles.

This image, which I believe you produced, shows repeated patterns in the
ciphertext:

<a href="https://i.imgur.com/MWmMc0J.png" rel="nofollow">https://i.imgur.com/MWmMc0J.png</a>

Likewise, there are severe failures on Chi Squared tests:

<a href="http://www.freecx.co.uk/cryptanalysis/Crystalline/" rel="nofollow">http://www.freecx.co.uk/cryptanalysis/Crystalline/</a>

Specifically:

<a href="http://www.freecx.co.uk/cryptanalysis/Crystalline/bias-result_(1)_10MB.txt" rel="nofollow">http://www.freecx.co.uk/cryptanalysis/Crystalline/bias-result_(1)_10MB.txt</a>

Overall Chi Squared value is 7474.808 (threshold 18.4753)
Overall likely non-uniform (>99%)

<a href="http://www.freecx.co.uk/cryptanalysis/Crystalline/bias-result_(2)_10MB.txt" rel="nofollow">http://www.freecx.co.uk/cryptanalysis/Crystalline/bias-result_(2)_10MB.txt</a>

Overall Chi Squared value is 13485.34 (threshold 30.5779)
Overall likely non-uniform (>99%)

<a href="http://www.freecx.co.uk/cryptanalysis/Crystalline/bias-result_(4)_10MB.txt" rel="nofollow">http://www.freecx.co.uk/cryptanalysis/Crystalline/bias-result_(4)_10MB.txt</a>

Overall Chi Squared value is 20607.94 (threshold 52.1914)
Overall likely non-uniform (>99%)

<a href="http://www.freecx.co.uk/cryptanalysis/Crystalline/bias-result_(8)_10MB.txt" rel="nofollow">http://www.freecx.co.uk/cryptanalysis/Crystalline/bias-result_(8)_10MB.txt</a>

Overall Chi Squared value is 45699.52 (threshold 91.81917)
Overall likely non-uniform (>99%)

I think the biggest problem though is all of this has already been pointed
out to you repeatedly in other forums and you completely refuse to
acknowledge that your cipher fails to meet the absolute most minimum
criteria for a secure cipher.

If your cipher were secure, this image would not contain obvious repeating
patterns:

<a href="https://i.imgur.com/MWmMc0J.png" rel="nofollow">https://i.imgur.com/MWmMc0J.png</a>

If your cipher were secure, it would pass all randomness tests.

There are many more requirements for a secure cipher, but your cipher fails
to meet the baseline requirements.

-- 
Tony Arcieri