FRA BA WRT EAR AY
On the popular appeal of steganography.
Wednesday, 2009-10-07 | Cryptology, Language
| "If Lord Bacon wrote the plays that have come down to us under the name of Shakespeare, it was his duty to leave to posterity the means of ascertaining the truth." |
| Hugh Black |
The earliest secret writing in human was, depending on who you ask (and his epistemological biases), steganographic.
In Kahn's Codebreakers, the first cryptographers are ancient scribes who would stylize and embellish the pictograms and ideograms of their ancient languages in a consistent manner, thereby creating a sort of code by which their authorship could be recognized: if the tomb's inscription featured winged snakes with curlicues for wingtips, then that meant that you were reading the work of Tim the Ancient Scribe.
If you believe, as Kahn does, that a "code" is found wherever a communicator intends to communicate two meanings at once--a plain meaning and a secret meaning--then those ancient scribes who had their own, personal, trademarked (as it were) cuneiform orthographies, were the first writers of code.
Obviously, people spoke in code long before they wrote in code. And, if we're sticking with Kahn's epistemology and recognizing a code wherever an utterance has "meaning" that is intentionally implicit, then the first coded language probably occurred in domestic settings: "why do you chew with your mouth open? It's disgusting" secretly meant "I had a shitty day and misery loves company, so here comes the antagonism" as much in Jericho as it does in Washington, DC.
At any rate, the earliest codes were steganographic codes: they were "hidden", as the cliche goes, "in plain sight" and the secret meaning they conveyed was there to be perceived by anyone with the organs of sense required to comprehend the communique.
In the more mathematically-oriented arts, steganography generally isn't admired for its technique, so much as it its for the messages it conveys. There are a number of reasons for this, but the primary reason that you seldom hear about modern cryto-enthusiasts geeking out about some clever piece stega is that if you're used to thinking about creating codes and breaking codes, steganography is very elementary, basic and generally requires very little computation. Basically, it's weak crypto.
And therefore, when crypto geeks get excited about a piece of steganography, it is because the "key" or solution to the steganographic concealment appeals to them on some aesthetic grounds. Consider the popular t-shirt:
There are 10 kinds of people in this world: those who understand binary notation and those who don't.
Crypto geeks, if they're going to really get excited (on an intellectual level) about a means of concealment, tend to prefer ciphers and encipherment, as those require technical know-how, an aesthetic sense and a degree of mathematical and logistical circumspection that aren't required to invent "good" steganography.
In the humanities, however, steganography is much more popular than encipherment as a means of concealing secret information. Consider famous obscuritanist Francis Bacon's so-called "cipher", which relied on printing a message in two different type faces and then moving through a text from left to right, recording whether each letter was in the "A font" or the "B font" by writing "A" or a "B" on your decipherment worksheet: break all of your A's and B's into units of five characters and then compare what you've got to your Bacon's "key" (the "magic decoder ring" here), which tells you that AAAAB = A, AAABA = B, AABAA = C and so on.
There's a very adequate Wikipedia Page on Bacon's "cipher"; there is also a nice summary here (scroll down a bit).
Bacon's "cipher" is only a "so-called cipher" because it is actually steganography: the plaintext is revealed by a very simple, monalphabetic substituation that, while it generally can't be done in real-time by the reader (and therefore requires a pencil and paper), doesn't rely upon anything more than obscurity for its security: everyone knew the key and you can't change the enciphering alphabet and those two facts mean that this is steganography, not encipherment in the technical sense.
At any rate, this sort of thing is more popular in the "humanities" than it is with the math-for-math's-sake crowd. And I'm no expert, but I think this is the case because of a peculiarity in the way that people with different types of personalities understand the world around them.
To a person sympathetic with Kahn's definition of what constitutes a "code", steganography is unimpressive because it's something you learn by rote. It's kind of like learning how to play a song. You learn it once, and you can do it over and over again with increasing competence. And if you believe that codes are constantly being used all the time (as, indeed, they must, if we believe what Kahn believes) in everyday communication, "secret" or "privileged" information that is concealed by a code is...well...it's not very well protected, on account of the very pedestrian nature of the technology used to conceal it.
If, however, you believe that there is something marvelous and remarkable about how and why humans communicate--as, indeed, you must to be a serious and effective student of the humanities--then steganography is wonderful. It's not so much that math and proper ciphers are hard: rather, steganography is the elevation of the implicit message to the same physical or perceptual level of the explicit message that changes neither message and is therefore a remarkable trick of language and comprehension.