Smalltalk & Cryptography



Start with a quick overview of cryptography techniques (one-time pad, symmetric/asymmetric keys)

Then, among the key-based techniques, some talk about stream vs. block-based techniques.

The presentation was supposed to be about cryptographic support within VisualWorks, but the coolest (and most effective) thing about it was that the presenter (Martin Kobetic) had gone through the trouble of assembling his slides in some software for VW that resembled book morphs in Squeak. Because his presentation was running in a live image, he was able to demonstrate some of the points he was making by running do-its.

This in itself is no big deal (who cares about seeing a string become a random byte array?), but when he was demoing the danger of reusing keys in a symmetric key system (RSA?), he ran the encoding on a clipped region of pixels within his presentation, then ran the same process (same key) on another clipped region, then overlayed the two regions, finally resulting in what was recognizable as the two clipped regions overlayed on one another.

(A xor: k) & (B xor: k) = A & B.

You had to be here, I guess. It was very effective. I think it was George Heeg who said that it was the best presentation demonstrating different cryptography techniques that he had ever seen, and I have to agree.

Posted: Mon - May 3, 2004 at 10:31 AM      


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