Re: CYPHERPUNKS TO THE RESCUE

I think Norm gets the prize for the best garage door opener:

> ...How about the car unit signing successive numbers....

But this raises an idle question: how much easier is it to break 
a DES key given a sequence of (n, DES(n)) where the n's are 
successive numbers, than it is if the n's are random (but still
known)?  I doubt this is a practical threat for garage doors.

- -Steve
- - - - - - - - - - - - - - -
nutritional information per serving:
   less than one (1) bit
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In message <9407261944.AA04628@smds.com> FutureNerd Steve Witham writes:
  > But this raises an idle question: how much easier is it to break 
  > a DES key given a sequence of (n, DES(n)) where the n's are 
  > successive numbers, than it is if the n's are random (but still
  > known)?  I doubt this is a practical threat for garage doors.

This would be a known plaintext attack, well suited to differential
cryptanalysis.

Though the lifetime of the average garage door opener is probably small
enough that it would die before you had enough plaintext/ciphertext
pairs for a good attack