Re: VMs: RE: Making a vms with meaning (long)

[Gabriel Landini <G.Landini@xxxxxxxxxx>]

On Monday 28 June 2004 08:51, Elmar Vogt wrote:
> As to solving such a code, I think you should look for words, which
>
> *) appear often,
> *) repeat often,
> *) are placed at the beginnings and ends of sentences/paragraphs,
> *) form characteristic sequences of two or more words.

Yes, given that you *know* the language this was written in, one can *guess* 
some very basic structural constructs. In English this would be "and the", 
"of the", sentence initial "The" and so on. But (as in the vms) you do not 
know the language of the PT.

> In english, a phrase like "for example" might be a good candidate for the
> last issue: While "example" overall is probably not a very common word, it
> frequently follows one particular, fairly frequent word -- "for".

Only if that appears in the text, which you do not know. Just suppose that the 
book is in English and it is about "my little pony". This would appear a 
large number of times, but how do you get to the word "pony"? Couldn't your 
approach still consider correct that the 3 word pattern could be about the 
"big red balloon" or "that fat dog"?

> Now compare those patterns/frequencies in your plaintext language
> (whichever it is...) with the VM statistics... and do a lot of guesswork...
> et voila!

I can send you the text and you can try it. I would say it would be extremely 
difficult, because as in the vms you do not know the PT language.

First you need to guess the language or propose it based on the word patterns 
out of a large number of language samples.
Then you can (perhaps) *guess* some of the most frequent words. I do not 
believe one can do anything else, unless you know it is a known piece of text 
for which you could try matching the pattern of word sequences (brute force, 
really).

> P.S.: Assuming that ciphertext words correlate to plaintext words 1:1, and
> in the light of the fact that the VM shows no punctuation -- wouldn't that
> mean that each VM paragraph is equal to one plaintext sentence? And
> wouldn't that in turn mean... awfully long sentences?

Punctuation was removed. But I could produced one version which maintained the  
full stops.

Cheers,
Gabriel


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