🚀 go-pugleaf

hollasch@kpc.com (Steve Hollasch) writes:
:     I was playing around the other day with developing a transcripted
: shorthand that is fairly secure.  [...]
:     So are there other tricks for developing such an encryption?  Are
: there any references for this sort of thing?  Also, does anybody know 
: how many different types of shorthand there are?

In the past few hundred years, a staggering variety of shorthand
systems have been developed.  Of course, their heyday is long past,
but most libraries still have some shorthand manuals on their shelves.
I suggest you check one out; the shorthand systems are often
quiet inventive.  The "compression" schemes devised to make 
shorthand succinct and easy to write quickly are similar to 
what you might devise for a simple crypto system.  The shorthand
systems, in general, are not just simple substitution ciphers.

I recall reading a story--possibly in _The Codebreakers_--of a
fellow who labored for decades on deciphering the volumnious
works of another deceased individual, works which were written
in an obscure shorthand dialect.  He succeeded in "breaking" the
system after years of intensive effort. But then shortly afterwards 
the "key" was found in the form of a description of the 
long-forgotten shorthand system.  Must have made him feel awful.

In article <1992Aug4.180852.11447@kpc.com> hollasch@kpc.com (Steve
Hollasch) writes: 
...
> I was playing around the other day with developing a transcripted 
> shorthand that is fairly secure.  
...
> What I ended up with last night is basically a simple substitution
> cipher with some tricks tossed in.  
...
> So are there other tricks for developing such an encryption?  Are
> there any references for this sort of thing?

I think there is a passage in _The_Codebreakers_, by David Kahn where
he discusses simple substitution-type ciphers like yours (I think it's
in a chapter on the early telegraph systems, but I'm not sure).

Anyway, I seem to recall the statement that simply removing all the
letter e's raises the security quite considerably.

(n.b.: I suspect that's sort of like saying adding 10^-4 to a number
like 10^-5 raises the value of that number quite a lot ... it's true,
but if you're on a scale of 0 - 10, who cares?)

-don

In article <1992Aug5.020416.8477@Princeton.EDU> dla@athena (Don Alvarez) writes:
>In article <1992Aug4.180852.11447@kpc.com> hollasch@kpc.com (Steve
>Hollasch) writes:
>...
>> I was playing around the other day with developing a transcripted
>> shorthand that is fairly secure.
>...
>> What I ended up with last night is basically a simple substitution
>> cipher with some tricks tossed in.
>...
>> So are there other tricks for developing such an encryption?  Are
>> there any references for this sort of thing?
>
>Anyway, I seem to recall the statement that simply removing all the
>letter e's raises the security quite considerably.

	If anybody finds a copy of the novel "Gadsby", let me know.
	It was written without using "e" (the letter, not the
	exponential function).  The vowel distribution is very different
	I can't remember what the changes were offhand, William Friedmann
	checked it out and that is good enough for me.

>
>(n.b.: I suspect that's sort of like saying adding 10^-4 to a number
>like 10^-5 raises the value of that number quite a lot ... it's true,
>but if you're on a scale of 0 - 10, who cares?)
>
	Alec Chambers

In article <1992Aug4.180852.11447@kpc.com> hollasch@kpc.com
(Steve Hollasch) writes:
>
>    This is a bit out of the mainstream of the topics in this group, but I
>think it's still in keeping with the main idea.
>
>    I was playing around the other day with developing a transcripted
>shorthand that is fairly secure.  Obviously this will be much weaker than,
>say, crypt or the DES, but I wonder if there can be some "reasonable"
>degree of security in a written code.
>
>    One of the limiting requirements is that I want to be able to write it
>down quickly, without doing calculations for each symbol, so it would have
>to be something like an substitution alphabet.  In addition, I tailored my
>symbols to be easy to write quickly; ideally I'd like to be able to write
>at a speed comparable to (faster than?) writing standard English text.
>
>    So what I ended up with last night is basically a simple substitution
>cipher with some tricks tossed in to lightly screw up letter distribution
>(since, in my understanding, the "etaoinshrdlu" attack is very effective
>for transcribed English code).  I basically did things like encode double
>letters differently, combine some symbols (like "ng"), drop vowels
>occasionally, and the like.
>
>    So are there other tricks for developing such an encryption?  Are
>there any references for this sort of thing?  Also, does anybody know 
>how many different types of shorthand there are?

This sounds sort of like a modern version of the "nomenclator" type
of code widely used in the middle ages.  Kahn ("The Codebreakers")
has a chapter or two on them.

- Jonathan Thornburg
  <jonathan@einstein.ph.utexas.edu> or <jonathan@hermes.chpc.utexas.edu>
  University of Texas at Austin / Physics Dept / Center for Relativity
  and (for a few more months) U of British Columbia / {Astronomy,Physics}

In article <1992Aug5.020416.8477@Princeton.EDU> dla@athena (Don Alvarez) writes:

! I think there is a passage in _The_Codebreakers_, by David Kahn where
! he discusses simple substitution-type ciphers like yours (I think it's
! in a chapter on the early telegraph systems, but I'm not sure).

! Anyway, I seem to recall the statement that simply removing all the
! letter e's raises the security quite considerably.

Perhaps you should use the writing method of the ancient Egyptians or
the current Chinese. Use one symbol to mean one word. Since this makes your
system harder to remember, you probably should use only some word-symbols
for things you write frequently about. But NOT for all of them. A cipher
that writes 'I', 'mother', 'Linda' with one symbol but 'father' and 'Peter'
letter by letter should produce some grey hairs for codebreakers. (Judging
by the fact how hard it was to understand the ancient Egyptian's writing.)

--
...............................................................................
Ari Huttunen                                         You don't miss water
                                                       until the well runs dry.
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