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Re: The War is Underway (fwd)



In article <[email protected]>,
Lucky Green  <[email protected]> wrote:
> Contrast this with DESX, which has been
> proven to be twice as hard as DES, therefore having an effective keylength
> of 112 bits.

Actually, that's not true.  Check out the Rogaway/Kilian paper.

It says that, if you've got 2^p known plaintexts, DESX has an effective
keylength of at least 118-p bits.  So, for instance, if you've got 2^32
known plaintexts, DESX only has an effective keylength of 86 bits.

In short, 3DES is (roughly speaking) stronger than DESX.