: At the company I worked for previously, I received a file that was
: des encryped
: and the person that had sent it, went on vaction.  Rather than wait
: two weeks
: I set up a straight frontal attack with one key at a time.  It only
: took two(2)
: days to crack the file.  No, I don't have any faith in DES.

Then it was either _really_ good luck or you had some _very_ fast
machine.  DES has 2^56 possible keys, each two of which are simply
to convert into each other, so you have to expect 2^54 trial encryptions
in the mean case, assuming known plaintext.
2^54 / 2 / (24*60*60) / 1000000 is ca. 104250.
So you must have managed to do 104250 encryptions per microsecond.
CE Infosys builds a very fast DES chip that manages 2 (!) encryptions
per microsecond.

Yes, I'm not very seriously bothered about the security of DES yet;
though you might prefer to use triple DES or IDEA, both of which
use more key bits.

joerg

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