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Trithemius progressive cipher

Jims Reds wrote:
>In fact this cipher is described in Trithemius's "Clavis 
>Polygraphiae" printed in 1518 with his "Polygraphiae Libri Sex":
>(in the section headed "Explantio in quintum librum polygraphiae
>nostrae brevis", fol. [B iv] = about p.531.)

>> Verum ut ordinem uideas, ponamus exe[m]plu[m]. Hxpf gfbmcz
>> fueib gmbt gxhsr ege rbd qopma uwu, wfxegk ak,
>> tnr qxyx. Huius mystici sermonis sententia est. Hunc caueto
>> uiru[m], quia malus est, fur, deceptor, me[n]dax & iniquus. 

>approx. trans:
>To show you the correct order, we give an example.  Hxpf ...
>...  The sense of this mysterious writing is: "Hunc caueto ... "

>Here Hunc gets enciphered as Hxpf because H+0=H, u+1=x (in the
>Latin alphabet without v or w), n+2=p, c+3=f, and so on.

So, Trithemius was in fact a C-Programmer (Fact:index started with 0 instead
of 1 ;-)).

Back to business:
This cipher has some interesting features (Garbriel Landini poited to this
1. Within a word no character will be encode twice to the cipher char.
2. The word structure will be preserved
3. This cipher will not change the entropy of the text.

So, if (and why not) our author of VMS used a cipher like this, how did he
produce a code with such low h2 entropy?
In discussion with Gabriel. I wrote a small programm an d applied the cipher
to some text in different languages. Even when adding some redundancy to the
code (like doubling every vocal), I was not able to produce  such a low
h2-entropy and not even come close to the h2-h1 number of the voynichese.
So I wonder, is there any coding scheme, which will produce such a low h2
and enlarge the average word length? 
Or, is the any language, with a low entropy -> high redundancy, with has a
low char count/word and prseverse such properties ?


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