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AW: VMs: Reducing the 2nd order entropy by sorting within words



Title: AW: VMs: Reducing the 2nd order entropy by sorting within words

My method drops double entries.And I think sorting of characters was only the 1st step in the encoding.I can imaginge, applying a progressive mono-alpha substition after the sorting and implementing some hints inside the encrypted word.This will result in a dictionary.

exhrt -> thre(e)
ehrtx -> ther(e) ...
Claus
PS: the progressive mono-alpha substition was discussed some time ago:the replacement would be depending on the characters postion within the word, thus avoiding letter freq. Peaks - if carefully chosen.

-----Ursprüngliche Nachricht-----
Von: Gabriel Landini [mailto:G.Landini@xxxxxxxxxx]
Gesendet: Donnerstag, 7. August 2003 19:09
An: vms-list@xxxxxxxxxxx
Betreff: Re: VMs: Reducing the 2nd order entropy by sorting within words


On Thursday 07 Aug 2003 10:12 am, Anders, Claus wrote:
> Just for fun I wrote a small awk program and let that work with some
> Latin text.It just sorts the characters with a word unique and guess
> what: the output h2 is as low as 2.277 (according to monkey).
[...]
> Seems, that sorting could be part of the encryption scheme.

I remember Rene's letter sorting as well, and I always wondered whether the
resulting text could be reconstructed. The dictionary idea would help. The
problem is that there are many solutions to a single character sorted word:

eehrt -> three, there ...

Character sorting would mean that one could not see word patterns in which the
letters go "backwards" (like "abca" and so on, since the sorting would put
the two "a" together).

Below are the frequencies of the most common 22 patterns (I found 969 word
patterns). The arrow "<---" shows those patterns that are not "increasing".

freq pattern
---- -------
5716 abcde
5610 abcd
3465 abc
3188 abcdef
2500 ab
2307 abccd
1548 abcdde
1282 a
1166 abcdefg
804 abcdeef
778 abbc
640 abccde
516 abcddef
448 abac <---
347 abcdefgh
335 abcbd <---
303 abcdeffg
290 abcad <---
274 abcdbe <---
263 abcda <---
245 abcdae <---
234 abacbd <---

cheers,

Gabriel

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