Breaking DES, Crypto (2)

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Disclaimer: artículo sólo para frikis, y para gente con ganas de ampliar conocimientos y/o aprender curiosidades.

DES stands for Data Encryption Standard. It's a ciphering algorithm widely used for secure computer communications. It was accepted as a useful and not very demanding - in computing resources terms - cryptosystem during quite a while. Nevertheless, weaknesses were discovered, which led to development of new algorithms. An improved version of DES was issued as Triple DES, but its slowliness diminished its impact. Thus, algorithms such as AES, Twofish, IDEA, etc, were created and implemented.

For my course on Cryptography (you already knew about this if you read Multinúcleos y Crypto(1) where I wrote about Deep Crack) I've recently had to produce a little research work and prepare a presentation mainly about differential cryptoanalysis and linear cryptoanalysis. I widened the spectrum a little bit for dealing with not only cryptoanalysis attacks, but also with bruteforcing DES cryptosystem, and including a couple of semi-depth reflections about the whole thing, in the form of food for thought: real possibility of chosen plaintext attacks, practical chances of cryptoanalyzing DES, limits of brute force, etc. I titled it Breaking DES.
At the end, the presentation took a long while more than had been expected (I was supposed to talk for 30-40min and i was there for about an hour), but I think the teacher was satisfied with my work... At least, that's what I hope.
Anyway, I learned quite many things I'd like to share with anybody interested in the subject, so that's why you can access the original .ppt here (in Spanish; all content under by-nc-nd Creative Commons licence). Were you not familiarized with technical aspects of cryptography, you could still find some interest in it, since there's a bunch of good references, links and plenty of bibliography to consult included (some technical, some historical, some just divulgational).

Any feedback would be much appreciated ;-)

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