At 03:44 PM 6/12/98 -0700, toback2 wrote:
>Both the German Enigma and the Japanese Purple were
>solved analytically, using a known-plaintext attack. In fact, Enigma was
>reconstructed by analysis well before the first one was ever captured.
>Both attacks relied on weaknesses in the system, not weaknesses in the
>algorithm, and the system is only partially under your control. (When the
>systems were improved, as in the German naval cryptosystems, analysis
>sometimes used a chosen-plaintext attack.) British codes were almost
>trivial to solve by analysis, and the Germans were doing so regularly
>until about 1943.

I seem to recall a number of other interesting aspect of encrpytion during
WWII.  I believe we succeeded in breaking the Japanese code and shortly
thereafter intercepted a message of a trip that Admiral Yamamoto (sp?) was to
take flying to a Japanese held island in the South Pacific.  The U.S. then
sent out a squadron which intercepted and shot down the plane carrying
the man who planned and carried-out the attack on Pearl Harbor.

In turn, the top-security encryption used by the U.S. during WWII was never
compromised.  The message was first translated into the Navajo language then
encrypted.  So even if the message was decrypted they couldn't be sure because
the language itself wasn't widely known or understood.  I seem to remember
that the Navajo language itself had never been documented either and was
only known to these native Americans.  I believe the U.S. had a number of
Navajo in the service solely for this level of classified communications.

I can't recall all the specifics, don't have all by cryptography material
here....

/jf
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                          Monday, June 22nd

           Today in 1944 - The "G.I Bill of Rights" granting educational
                           and vocational benefits was passed.

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