Re: Plaintext

Evan Jeffrey (ejeffrey@eliot213.wuh.wustl.edu)
Wed, 02 Jul 1997 22:17:15 -0500


>If, as in the real world, you can't necessarily tell when you've found
>the decryption of any layer but the last layer, breaking a triple 56-bit
>RC5 by brute force will take you (2^56)^2, rather than 3, times as long
>as breaking a single 56-bit RC5 also by brute force. :-)

except that many triple DES implementations use the same key for the first
and third encryption. So it is really "double DES + some an extra
encryption to make it look noisy"

As for triple RC5, I don't know why one would do that, since the RC5
algorithm is parameterized to allow key sizes of up to 128 bits already.

===
Evan Jeffrey
erjeffre@artsci.wustl.edu

The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore all progress
depends on the unreasonable man.