Talk:Feistel cipher
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Matt,
Perhaps Schneier and Blaze's MacGuffin should be added to the list? Thanks for the assist at padding. I'm going to look it over now. Oops about windowing vs winnowing. Remember the grey matter.... It's increasing the leak rate. Pretty soon I'll be suitable for a problem in introductory calculus.
ww 20:21, 12 Apr 2004 (UTC)
Missing part in the model of the structure
I was struggling with showing that encryption and decryption is the same (except for the reversel of the key order) in an assignment in my studies. I tried using this article as a basis to understand it, but discovered after a while that there is a minor flaw in the figure of the structure.
After the last round in the feistel structure is run, there is an extra flip of Ln/Rn, making the result of the last round and the entire process different. This is important when trying to understand why it works to run the same algorithm for decryption as for encryption.
You can see a correct model in William Stallings' book Network Security Essentials, on page 33, in the 2nd edition of the international version of the book.
Andre Rakvåg
Student, Norway
- I believe the diagram is correct, since two swaps is equivalent to no swaps. Lunkwill 19:18, 6 Jun 2005 (UTC)