CS591 ST 008

Lab 1 (due 2/25/09) 2nd week

I have talked with the professor about how to solve the 16 bit k3 key in this lab.
I have written up a pseudo code to help me gather my thoughts.
Email sent back to professor with my pseudo code example.
Sent this pseudo code to the chat mail list to get feedback.
Read chapters in book dealing with DES; not helpful.
I need to spend more time looking at linear.cpp for how this is done.
Used professor's new S-boxes in code.
I think I now finally understand what I need to do to find the key, the only part that seems difficult is the linear equations.
I still don't understand how a linear equation that is correct a high percent of the time means I have a potential K3? And what good is K3 going to do us without K1 and K2. We cannot decipher the secret.ciphertext without all the keys.

I have started putting the pseudo code into a C++ program. I'm trying to reuse most of sdes16v2.cc.