As long as you allow the encoded text will be longer than the original one, it's no problem to lower the entropy.But my restriction is, the encode text should have the same count of chars.
If I just double every char,I'm getting a low entropy for sure (h0=4.5, h1=4.06, h2=2.6).
I could try an encoding schema (suggested by Nick) based on 'syllable" pairs, and look at the entropy.
Claus
-----Ursprüngliche Nachricht-----
Von: Gabriel Landini [mailto:G.Landini@xxxxxxxxxx]
Gesendet: Donnerstag, 20. März 2003 10:42
An: vms-list@xxxxxxxxxxx
Betreff: Re: AW: VMs: context sensitive encoding
On Thursday 20 Mar 2003 7:38 am, Anders, Claus wrote:
> BUt I think now, if you encode a text with cipher, no coding algorithm
> exists, which can lower the h2 entropy of a given text to the VMS level
> without lengthen the text.
There are such codes:
http://web.bham.ac.uk/G.Landini/evmt/daindaiin.htm
and as a consequence, many others substitutions of this kind. I don't think
that the vms is coded this way, but this even lowers the entropy lower than
the vms as encoded in EVA. To me, the low entropy of the vms is remarkable
and tells something about how the text may be built, but it is not so strange
as Bennett thought.
> As the average
> token length is short (compared to most known languages), there can only be
> few 'nulls'.I don't believe (but has to be proven), that a few nulls can
> lower the h2 drastically.
Yes it can, see the rticle above and:
http://web.bham.ac.uk/G.Landini/evmt/commas.htm
(last graph).
On top of that, the text can still be read back pretty well. Weird, isn't it?
:-)
Cheers,
Gabriel
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