From: Robert Klemme <bob.news@...>
Date: 2004-08-19T21:00:53+09:00
Subject: Re: POT (partly offtopic) Re: Q: Shifting a hash anf and array


"Meino Christian Cramer" <Meino.Cramer@gmx.de> schrieb im Newsbeitrag
news:20040819.123945.92579085.Meino.Cramer@gmx.de...
>
>   Sorry, Robert! This was only a nonsense joke. The only thing I
>   wanted to say was, that your non-rotating-but-offsetting-algorithm
>   will improve (therefore a kind of "incrementation of the Enigma
>   code") the code of the Enigma. Nothing more...

Ah, ok. :-)

> > Good luck!  Some links that Google revealed:
> >
> >
http://www.mirrors.wiretapped.net/security/cryptography/algorithms/enigma/
> > http://www.javaworld.com/jw-08-1998/jw-08-indepth-p3.html
> >
> > http://mathforum.org/library/topics/cryptography/
> >
> >
> > Kind regards
> >
> >     robert
>
>
> That's really funny, Robert!
> What do you think, how often I hammered keywords like "Enigma",
> "cryptography and such into Google the last days...but I never stumbled
> across these...

I searched for "enigma algorithms".  I think they're all on the first page.

>   Each wheel has a notch (or two), which will turn "the next" wheel
>   one step at a certain point of rotation -- like the carry bit used
>   in assembly programming. I implemented this notch as a object
>   variable, which is set true at the position in question and has to
>   be evaluated by the "next wheel"-object.
>
>   Like this?
>
>   @carry=true # cause the first rotor is always rotated by one step if
>                           # a new letter arrives to be encoded
>
>   encoded = objarray.inject(letter) {|param, rotor|
>                   rotor.rotate(@carry)
>                   @carry=rotor.carry
>                   rotor.encode param
>                   }

or

encoded = objarray.inject( [letter, true] ) do |(param, carry), rotor|
  rotor.rotate carry
  [rotor.encode( param ), rotor.carry]
end.shift

Regards

    robert