


This has to be a dictionary attack.  No other attack makes sense.


This means that whoever encrypted the file just typed some password
which was a single dictionary word, and then Russell tried all the
words in the dictionary.  This isn't too implausible, especially if he
was smart and clipped the first plaintext block off the ciphertext (if
the first block doesn't decrypt then obviously the others won't
either).

Assuming one attempt a second, it takes seven hours to try all the
words in /usr/dict/words.   Not real tough.

If you want DES to be secure, you have to use RANDOM KEYS.  You can't
just type your wife's name and think "aha they'll never guess that
one!"



-- 
Daniel F. Boyd -- boyd@cs.buffalo.edu 