double encryption

Peter T. Abplanalp
Tue Jun 11 15:59:02 2002

On Tue, Jun 11, 2002 at 03:59:15AM +0200, Volker Gaibler wrote:
> A DoubleDES cipher (encrypting two times with SingleDES and two
> different keys) has an effective key size of only 1 bit more than
> SingleDES. This is not really stronger than the single
> encryption - and DES is a really good cipher (only it's key size is much
> too small). There are even (theoretical!) examples where cascaded
> encryption can weaken a cipher. But that's really theoretical.

hmmmm.  isn't 3DES just DES 3 times?  given the above, how much
stronger is 3DES than 2DES and DES?

Peter Abplanalp