Limited Entropy Dot Com Not so random thoughts on security featured by Eloi Sanfèlix

Crypto Series: DES and AES Visualization

Thanks to previous posts in this series we already know how the DES and AES ciphers work. Now we'll use ryptool to get a better understanding of these algorithms and see how every one of the described steps works.

To this end, we first launch Cryptool and then go to Indiv. Procedures > Visualization of Algorithms > DES to see the DES algorithm. We'll get a window which will show the different steps in the algorightm, together with navigation controls that we can move somewhere else if they are placed on top of part of the animation due to our screen resolution.

This image shows one of the steps in the DES visualization:

DES Visualization

For AES we have two options. The first of them, which can be found in Indiv. Procedures > Visualization of Algorithms > AES > Rijndael animation, provides a Flash animation explaining every step in the AES cipher.

AES Visualization

The second one, accessible through Indiv. Procedures > Visualization of Algorithms > AES > Rijndael Inspector, allows us to see the AES state in every intermediate step throughout the algorithm. This would allow us to check an hypothetical AES implementation:

AES Inspector

As you can see, once again Cryptool proves itself as a valuable educational tool for Cryptography, both classical and modern algorithms.