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## Journalnickull's Journal: Semaphore Code - can Slashdot users crack it?

For those of you who love a challenge, Adobe has sponsored a whopper. The Semaphore art project in San Jose is where art meets technology. Four large round glyphs rotate their position every 7.2 seconds while a simultaneous low power radio broadcast emits a coded message. Artist Ben Rubin's mind shred's message seems to follow a pattern. Each broadcast segment contains an audible analog tone, an audible analog pattern, followed by a string-integer hash. Several items vary during the broadcast including the tone of the woman's voice as she speaks the integers. The tones also change.

Here is a pattern:

Tone, dot pattern, click(ping), string, integer, ping

Here are some general observations that might help those trying to decode it. I also want to state that while I do work for Adobe, I have in no way had any internal knowledge of this project nor do I have any keys to the answer.

Background:

Semaphore is an ancient flag based signaling system. A person holds two flags and uses one rotational angle to act as a key while using a second flag to indicate a specific value. The comparison to the rotating glyphs cannot be ignored.

1. What is the significance of the glyphs changing position every 7.2 seconds? This could be a key or it could be incidental to the entire exercise. I would suspect that due to its' precise timing, it is a key.

2. Ben Rubin's education should probably be factored in. There are no details of him ever studying cryptographic techniques. Accordingly, I would presume the cypher's key to be less complex than Rinjdael's (AES) et al. I did find his master's thesis entitled "Constraint based cinematic editing" which may be a clue into his mind.

3.What possible significance does the tone of the woman's voice have? It seems to speak in two tones - one about one octave higher than the other. It this significant of some kind of logic gate?

4. What are the string-integer pairs. Here is an example:
India 02
Kilo 08
Echo 06
Delta 01
Charlie 05
Mike 03
Mike 14
Echo 06
Delta 04
Delta 04 (note repeat)
India 02
Kilo 08
Echo 06
Delta 01
Charlie 05
Mike 03
India 02
Delta 15
Delta 04
Mike 14
Alpha 10
Delta 04
Delta 04
Alpha 10
Charlie 16
Delta 15
India 02
Delta 15
Delta 04
Mike 14
Alpha 10
Delta 04
Delta 04
Alpha 10
Charlie 16
Delta 15
Delta 01
Pumpkin 02 ??
Kilo 03
November 04
Charlie 11
Charlie 16
Lima 03
Echo 06
.....

Note the pattern repeats certain characters (Delta 04's seem popular). There are alsio patterns of repetition that seem to repeat above a statistically normal basis. Based on this I would aver that the answer is a value of text. The same values suggest double letter combinations in the resulting text (example = Challenge has two "ll"'s)

While the Semaphore Flag code uses only 9 positions, note that the numeric values scale much higher. Could this be a revision of the code based on some key (7.2) to reflect the glyphs ability to provide a more precise rotational index? I did not encounter any numeric value over 16 while listening.

The Semaphore art uses the NATO phonetic alphabet.

A: Alpha
B: Bravo
C: Charlie
D: Delta
E: Echo
F: Foxtrot
G: Golf
H: Hotel
I: India
J: Juliet
K: Kilo
L: Lima
M: Mike
N: November
O: Oscar
P: Papa
Q: Quebec
R: Romeo
S: Sierra
T: Tango
U: Uniform
V: Victor
W: Whiskey
X: X-ray
Y: Yankee
Z: Zulu

Note that "Pumpkin" is not actually part of the phonetic alphabet. Perhaps I heard it wrong.

Good luck - anyone with Theories, please post them back to this blog. Maybe we can get lucky....

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