sure is quite around here; (n/t) (jeff) 

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for jeff
 Thursday, 18-Nov-1999 14:43:59 

      194.78.233.12 writes:

      Hi jeff,

      regarding the last part of your previous post.

      Indeed, I'm assuming UF BG - > SE ND
      But this mean only that UF -> SE and BG -> NF ... not fb->en. We are working with pair of letters starting always after the
      previous one (not crossing over each other).
      That's the reason why, for example, removing the first letter of the cipher don't work, because if you do, you will see that you
      get lot of digrams like EE, FF, GG which CAN'T occur in playfair.
      Use Tx's visual aid to write down your cipher-plain text and then work only on the pair separated by Tx. 

      Let me use one last example. I said i assume UF BG -> SE ND. Let's try to build a matrix with that. 

      First : UF -> SE
      this can give the following rectangle or lines (both vertical or horizontal)

      U S   S U   F E   E F  
      E F   F E   S U   U S
      S U ? E F    ? S U E F     S U E F ?    F ? S U E 
      E F ? S U    ? E F S U     E F S U ?    U ? E F S



      Second : BG -> ND

      N B   B N   D G   G D
      G D   D G   B N   N B 
      N B ? D G    ? N B D G     N B D G ?    G ? N B D 
      D G ? N B    ? D G N B     D G N B ?    B ? D G N 



      I hope i did not made any mistake.
      Anyway, after you got that, you now have to 'assemble' those 2 rectangles. As there are no letter in common, there is an
      'infinity' of possible way to arrange them. One could be for example :

      U ? E F S
      ? ? ? ? ?
      ? ? ? ? ?
      ? D G N B
      ? ? ? ? ?



      But you have to remember that, after the key, the missing letters are written in alphabetical order. In the previous example, I
      come with the result of a key length of more than 19 letters (Up to the B, cause N B is not alphabetical order), which seems
      very improbable.

      Well, you know what I am supposing for those 2 rectangles. Unfortunately, we need more know 'rectangle' to be able to fill the
      gaps and choose the right rectangle to use.... And so I come to the same result as before ... We need more plain-cipher text
      pair :(


      Hope this definitaly helps you to build matrix :)

      btw, if you hear of Jim coming here, please drop me a line ... I want to thank him for the opportunity he gave us to meet, work
      and, last but not least : have fun :)

      Regards,
      Laurent. 

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Re: aaaaaaaaaarrrrg; thanks Laruent!
 Thursday, 18-Nov-1999 17:32:42 

      208.128.132.37 writes:

      I haven't done anything on this today; I spent most of the day forfilling a promise:
      u can see a rough draft of my messageboarding essay here:
      http://www.jps.net/jas/essaymb.htm
      (Im to tired to make it an actice link...)
      oohooooookay
      essay here

      will have no time today to do anything else; must take car in for repairs and then my daughter has a choir shindig tonight;
      proud daddy will be there; she has several solo's!

      thank u Laurent...dam I have been doing it wrong this whole time...could be a reason why I couldn't get my brain around how
      to do it...:)

      thanks all;
      Cya tommorow then
      D-Day 

      jeff 

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4 Jeff (off topic) : fire in the sky 
 Friday, 19-Nov-1999 01:27:48 

      193.158.164.177 writes:

      Hi Jeff, 

      Yes, today could be D-day (though I do not believe that they will post any explaining essays before monday. Should we really
      find not the correct encryption : are we losers ? Surely not - just because we learnt a lot on our way (at least me). And there
      are still 2 tasks we can work on, even if they post the solution. 

      But, today is more than D-day. Looking at your new essay it seems like birthday and X-mas on the same day ! This is a
      #99-ing good essay ! What a fine work ! There are a wholelotta things to learn and test, so even if they do not give us the
      solution before monday, I will surely have no dull weekend (though I am still busy installing OS-es and proggies on my new
      puter, hope I get finished soon). 

      So all I can say in my lousy english : THANK YOU, Jeff - wizard of the messageboards ! 

      Regards + respects 


      The Seeker 

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