So, I screwed up the DES example somewhere I think. I’m fairly sure, anyway. Yeah.
Somewhere in:
First 8 iterations of DES Example
I made a mistake. I’m fairly sure the setup was correct:
Initial DES Setup Steps
And the first few iterations:
DES Iteration 1
DES Iteration 2
DES Iteration 3
You can see where I botched R’(2) by shifting the wrong values around.
Then F(3), K(4), R’(4), C(6), K(6), F(5), R(5), R(8), D(9), K(9), F(8), R(9) …
DES Iteration 4
DES Iteration 5
DES Iteration 6-7
DES Iteration 8
Those are the errors I found while I was working.
I’m also fairly sure that at some point I started getting R and L confused, in F most likely, when I’m XOR’ing. And I just didn’t have the … energy to go through it all to find the issue. I may work it after thanksgiving, or I may restart it in a more structured manner that will force me o keep track of the C D L R in proper manners.
OTOH, If I ever get this done properly and find a good way of displaying it, this is basically what I started this blog for. Showing the process, so that it’s easier to grasp, rather than just the mathematics and the sometimes hard-to-follow standards definitions. Not that I’m looking forward to MD5, RSA or Blowfish, for example 