

History PhD Student Reaches out to Cryptographers to Help Break a Civil War Code - justine
http://diarycodebreak.wordpress.com/

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lignuist
Since he was using very uncommon symbols and the cipher is old, it's not so
unlikely, that the author used a simple letter replacement table. Something
like:

a -> #,

b -> *,

c -> =,

...

and so on. Unfortunately the handwriting is a bit messy and hard to read, but
I'd try to make a frequency table for every symbol and compare that to a
frequency table of letters in the english language:

<http://en.wikipedia.org/wiki/Letter_frequency>

Now try to replace the most frequent symbol with e, the second most frequent
symbol with a or t and so on. Try some variations and look, if it makes any
sense.

~~~
Locke1689
If those pictures are the only coded messages letter frequency may not have
enough ciphertext to run on reliably.

~~~
lignuist
True, but that's why I'd try some variations.

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stickfigure
It will take a major feat of cryptanalysis just to decipher the guy's
handwriting, let alone the code parts.

Thanks for reminding me why I work with computers.

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jerfelix
Here's the first four images... ready for parsing by your program:

:::: image 1, left:

s-tac-toe equals minus-dot seven ex comma slash-slash-backslash gamma
capital-l lower-j ex slash

:::: image 1, right, downward

capital-t capital-i equals four parallel-lines slash-slash-backslash equals-
slash comma s-tac-toe slash-slash-backslash slash-slash-backslash-backslash
comma

:::: image 1, left, upper

capital-l divided-by capital-i comma equivalent comma lower-j comma capital-f
slash-slash-backslash capital-i squared-capital-n zee slash-slash-backslash-
backslash comma divided-by slash-slash comma slash-backslash-backslash slash-
slash minus-dot slash-slash-backslash

:::: image 2

plus-dot plus leaning-heart upsidedown-t minus vertical-line ex comma

leaning-heart capital-m capital-i capital-a minus three-peaks comma vertical-
line crap capital-b close-bracket plus script-j script-s lower-d comma

u-bar three-peaks capital-i

:::: image 3

capital-l backslash divided-by c-slash-slash capital-i comma capital-i
equivalent divided-by slash-slash-backslash-backslash comma capital-i minus-
dot three-horizontal-two-vertical ex comma equals zee capital-l

l-in-l 11-over-1 comma y-slash-slash slash-slash-backslash-backslash comma
capital-i divided-by comma minus-lower-dot c-omega slash-slash slash-i
11-over-1 slash-slash square-c equals capital-l equivalent slash-slash comma

capital-l slash-slash slash comma l-on-l plus slash-backslash-backslash slash-
slash-backslash-backslash comma 1-slash-1 11-over-1 capital-z comma capital-i
equals ex comma j divided-by c-slash-slash slash-slash capital-l divided-by
slash-slash ex comma

:::: image 4 (repeats image 2)

plus-dot plus leaning-heart upsidedown-t minus vertical-line ex comma

leaning-heart capital-m capital-i capital-a minus three-peaks comma vertical-
line crap capital-b close-bracket plus script-j script-s lower-d comma

u-bar three-peaks capital-i

~~~
jerfelix
Here's a frequency chart of the first 3 images:

(23, 'comma') (10, 'capital-i') (8, 'slash-slash') (7, 'divided-by') (7,
'capital-l') (6, 'ex') (5, 'slash-slash-backslash-backslash') (5, 'slash-
slash-backslash') (5, 'equals') (3, 'plus') (3, 'minus-dot') (3, 'equivalent')
(3, '11-over-1') (2, 'zee') (2, 'vertical-line') (2, 'three-peaks') (2,
'slash-backslash-backslash') (2, 'slash') (2, 's-tac-toe') (2, 'minus') (2,
'lower-j') (2, 'leaning-heart') (2, 'c-slash-slash') (1, 'y-slash-slash') (1,
'upsidedown-t') (1, 'u-bar') (1, 'three-horizontal-two-vertical') (1,
'squared-capital-n') (1, 'square-c') (1, 'slash-i') (1, 'seven') (1,
'script-s') (1, 'script-j') (1, 'plus-dot') (1, 'parallel-lines') (1, 'minus-
lower-dot') (1, 'lower-d') (1, 'l-on-l') (1, 'l-in-l') (1, 'j') (1, 'gamma')
(1, 'four') (1, 'equals-slash') (1, 'crap') (1, 'close-bracket') (1,
'capital-z') (1, 'capital-t') (1, 'capital-m') (1, 'capital-f') (1,
'capital-b') (1, 'capital-a') (1, 'c-omega') (1, 'backslash') (1, '1-slash-1')

~~~
larrydag
There are definitely more symbols then there are letters in the alphabet. So
that could mean he has multiple ciphers or that some symbols are substitutes
for words, possibly common phrases.

~~~
betawolf33
Though I was advocating this as a possibility, I should point out that he
might include some actual punctuation in the cipher as well as the standard 26
characters, so it's still possible that it's just a substitution cipher.

Additionally, it's possible that some of these characters aren't characters at
all, but common repetitions. I'm thinking particularly of those slashes and
backslashes.

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efsavage
I've somehow been conditioned to think of these Civil War diaries and letters
as full of flowery prose and beautiful handwriting. It's actually amazing to
me to see someone writing plainly and with handwriting almost as bad as my
own.

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deserted
Forwarded to a cryptography Professor and some of his students : )

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freeak
Is this what is needed?:

1\. Assign ascii to the symbols in the code

2\. Transcribe the code to ascii

3\. Solve the code in ascii using techniques from Snyder and Barzilay

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deserted
Yes.

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madao
perhaps its a form of shorthand

[http://upload.wikimedia.org/wikipedia/commons/thumb/e/ef/Ecl...](http://upload.wikimedia.org/wikipedia/commons/thumb/e/ef/Eclectic_shorthand_by_cross.png/200px-
Eclectic_shorthand_by_cross.png)

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indubitably
It's astonishing to me how little understanding people have of Unicode.

