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British WW II Codebook Online
An A.C. pointed out
Keith Lockstone's website
which contains a complete scan of the Second World War codebook
"British Cypher No. 5." An interesting look into history.
"...when on 10 June [1943] the Admiralty at last replaced Naval Cipher No. 3 with No. 5, which proved quite
secure, it was plain that the U-boats could never regain their former authority."
A good test of a crypto system is the amount of random data that is used to encrypt/decrypt.
If everybody downloaded a copy of a crypto system that was the same, and used it without providing random data all copies would scramble exactly the same way.
The German Enigma cipher only used enough random data to produce about 19600-531400 possible unique keys.
The theoretical random setting of three or four rotors each having 27 characters of the alphabet provided the random factor. The rest of the enigma machine was hardwired and would substitute characters in a fixed knowable way.
Minimal contemporary crypto systems use enough random data to produce at least 2^72 unique keys. As technology is bringing the cost of cracking these systems lower and lower these large numbers will soon seem ridiculously small.
It could be argued that many contemporary crypto systems use pseudorandom data to encrypt. Often times the actual number of likely keys produced is a subset of the theoretical number possible.
Much handier than printing out a couple dozen GIFs :-)
Best,
Adam
The number tables exhibit a weakness that is best explained by this article on the New Scientist Web Site.
Benford's Law (see the above article) states that given a random assortment of real-world numbers, 30% will start with a 1, 18% start with a 2 and so forth. Because the table lists the same number of values for each number, it follows that the numbers beginning with '1' will be used a lot more. Although unlikely, this may compromise the security of the code if it is used to encrypt numbers extensively.
You can check Benford's Law for yourself. Try it with share prices; career earnings of sportspeople, movie stars or racehorses; areas or populations of countries; all real-world numbers on the first 10 pages of any newspaper; and so on.
Because Benford's Law wasn't discovered until after the cipher was created, it is understandable that the cipher did not allow for this odd property of numbers.
--
The only thing necessary for the triumph of evil is for good men to do nothing. - Edmund Burke
...it still doesn't come close to the US using the language of the Navajo people to send out encoded messages. This was the only US code the Japanese never cracked. And tragically, it may soon be lost to us, too. There is somewhere around 50 or 60 speakers of Navajo left in the world.
--
Matt Singerman
Matt Singerman
http://matt.vegan.net/
Oh man, if the Germans invent a time machine, we're all screwed...
Bill Clinton: Pimp we can believe in. - The Shirt!!!
..you are on a slow modem !!
The scanned images (each 200-800K) take fscking ages to upload and jammed my browser (Netscape) for a while.
Not all of us have DSL or Cable modems
Donte Alistair Anderson Roberts - hi son!
Karma: Chameleon
This is doubtless not proof against the serious cryptographers of the NSA, but it would be most entertaining to have a PalmPilot utility for it...
If you're not part of the solution, you're part of the precipitate.
(Windows 95 is banned, under the Geneva Convention.)
Seriously, can someone add this to the International Patches, just for the fun of it? :) (Ok, well, maybe not so seriously, then! :)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
If anyone finds this stuff interesting, go out
RIGHT NOW and buy "The Code Book" by Singh. It
details the complete history of Codes and Ciphers
and includes many great examples of how they
were used/cracked. Amazing read!
--- witty signature
Second, BEWARE. This page is lame - all gifs on a single page, and they are HUGE. For my own purposes I downloaded them with wget, converted to ps and finally produced one single PDF file. You can download it here. This is my student account, and in Germany, so if someone can put it for all the slashdotters in USA on an american server and notify me I would be grateful.
Regards,
January
I suspect you have confused the Navajo with some other Native American tribe, as the Navajo are not nearly extinct but are, in fact, the largest tribe in the US.
The Navajo live in the Four Corners region of the southwest (the intersection of Utah, Arizona, Colorado, and New Mexico) on a large reservation. You can easily find their reservation on a map of Arizona.
While the Navajo population had been reduced to about eight thousand after the United States' war with them -- run by the infamous Colonel Christopher "Kit" Carson -- concluded in 1864, their numbers greatly recovered upon their return to northern Arizona. They are now the largest Native American tribe, having approximately ninety thousand members according to the 1990 census. And they continue to speak Navajo.
You can read a very short discussion of the Navajo code talkers on the NSA Museum's page at www.nsa.gov/museum/talkers.html.
If you are interested in general information about the Navajo, including their history and rituals, check out: www.ancestral.com/cultur es/north_america/navajo.html.