VMs: Polymorphic cipher (sorry for the confusion)

["Jeff" <jeff@xxxxxxxxxxxxxxxxxxxxxx>]

Please read the following and let me know if it is plain enough. I guess I'm
just rubbish at explaining things. Sorry.

Jeff

----- Original Message -----
From: "Jeff" <jeff@xxxxxxxxxxxxxxxxxxxxxx>
To: <vms-list@xxxxxxxxxxx>
Sent: 21 December 2003 00:26
Subject: Re: VMs: Three frequency tables


> Nick Pelling incoming@xxxxxxxxxxxxxxxxx
> 20 December 2003 17:08
> Subject: Re: VMs: Three frequency tables
>
>
> > Hi Jeff,
> >
> > At 16:38 20/12/2003 +0000, Jeff wrote:
> > >Dennis tsalagi@xxxxxxxx wrote
> > > > But what else are you thinking of?  Do you mean that
> > > > you don't think the gallows are just markers for cipher
> > > > change?  (I've never liked that either, but that
> > > > because it doesn't look like a polyalphabetic cipher to
> > > > me.)
> > >
> > >The VMS is a polymorphic alphabetic cipher. There is a difference.
> >
> > What is a "polymorphic alphabetic cipher"? What is the difference
between
> > one of those and a polyalphabetic cipher?
> >
> > Cheers, .....Nick Pelling.....
> >
>
> The polymorphic cipher will not give a letter for letter substitution.
Like
> a polyalphabetic. However single substitution is not used. An example.
>
> Take a line from the VMS.
>
> shoy.ckhey.kodaiin.cphy.cphodaiils.cthey.she.oldain.d
>
> We need to analyse this with all spaces removed. The analysis will look
for
> triplets of EVA characters. It could also be applied to a text with cth
etc
> substituted with single letters if that is your preference. You then get a
> table of occurance counts part of which is shown below.
>
> cho - 522
> iin - 376
> aii - 357
> dai - 255
> hol - 253
> hor - 234
> chy - 231
> cth - 208
> sho - 186
> tch - 163
> kch - 162
> che - 148
> hod - 98
> otc - 95
> cha - 86
>
> The numbers indicate how many times the triplet occurs, both within VMS
> words and across word boundaries. When we begin to plot letters for these
> individual triplets we can start to place conconant and vowel positions.
> Here is the same part of the table partially filled in.
>
> cho - 522 e
> iin - 376 e
> aii - 357 l
> dai - 255 l
> hol - 253 l
> hor - 234 r
> chy - 231 o
> cth - 208 i
> sho - 186 e
> tch - 163 n
> kch - 162 c
> che - 148 c
> hod - 98  r
> otc - 95  e
> cha - 86
>
> Here is the same line above using the full table with assumed
substitutions.
> Where each identified triplet stands for one letter.
>
> __e_.__cci.lacalle.dico.decarallio.__ici.__e.istale.n
> shoy.ckhey.kodaiin.cphy.cphodaiils.cthey.she.oldain.d
>
> Note the "phrase" la calle dico de carralio. Letters always resolve into
set
> positions with this method. If you already have the pattern d_c_ it will
> usually place an i between the d & c and an o after the c. The VMS
patterns
> do this automatically and cannot be influenced by changes to the method.
> Syllable formation just happens automatically. Unlike my previous attempts
> with pairified ciphers, illegal multiple vowel and consonant groups just
> don't form.
>
> Each triplet final glyph position will stand for a single substitution
> letter for that triplet only. So an h at the end of kch will produce a
> different letter than the h at the end of cth. Hence polymorphic. The
> pattern changes with varied pathways through the table. This is the
> information I sent to Jacques Guy that he used for his own cipher and
which
> produced the interesting entropy values.
>
> If his tests on Latin, German and Greek differ in any way from his English
> tests then that will be very interesting.
>
> NOTE A high percentage of triplets occur with below 20 occurances and
could
> be links to realign word ending patterns to maintain the repetative
> structure. The entropy match alone seems significant. However I am now
> finding a divergence from Italian using some new tests. This could arise
> from the forced structure imposed on the text. This would disrupt any
> attempt to do language pattern matching.
>
> My next step is to analyse triplet distances, where I select two distinct
> triplets and measure average distance between them on lines where they
both
> occur. If these numbers are consistent then I can assume syntactical
> structure and not simply random mechanical construction.
>
> Again all comments welcome.
>
> Jeff
>
>

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