Re: Steganography

[tcmay@netcom.com (Timothy C. May)]

Kragen Sittler writes:

> I headed to the library to check out what they had, crypto-wise.  I found one
> book copyright 1939, which had a chapter on methods of steganography.
> 
> Some of the suggestions I got from it:
> 	-Use every third letter of each word.
> 	-Use every nth letter of each word, where n varies depending on a key.
> (e.g., 2-4-1-5-5-3)
> 	-use every nth word of a sentence
...rest elided...

Was this "Cryptanalysis," by Helen Gaines? Or the Herbert S. Zim
popularization? Both are very dated.

Somehow I don't think 1939 methods will be real useful in a 1993
world. But the book may be educational...you have to crawl before you
can walk, etc.

(Kahn's "The Codebreakers" has some good stuff on hiding messages,
mostly from World War II...think about it, those spies may've used
your 1939 book as a tutorial!)

There haven't been many recent books dealing explicitly with
steganography, though modern crypto texts like Brassard's "Modern
Cryptology," the Antichrist's "Cryptography and Data Security"
(Dorothy Denning), or Salomaa's "Public Key Cryptography" are good
sources. And conference proceedings (annual "Crypto" conferences)
should have some articles on "covert channels" and the like. You can
find these books in (most) large university libraries or in (many)
technical bookstores.

If the only crypto book you have access to is from 1939, find a larger
library.

Happy reading!

-Tim May

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