Sorry for not posting much recently. The reason is simply life’s busyness, partially due to work I’ve been doing for my cryptography class (I’m getting my masters). We just took the final exam last night, so perhaps I’ll be blogging more in the coming month. That being said, I enjoyed the class and learned lots about cryptography.

Much of my time recently was spent working on our final paper. I, with a colleague of mine (Mr. Davis!), chose to investigate secure variants on the Hill Cipher, which is a matrix multiplication encryption scheme first purposed in 1929 by Lester Hill. We implemented the modern versions of the cipher with computer programs and learned quite a bit in the process. Here’s a link to our paper and our presentation.

Also related to cryptography, I’ve been following a bit of the news on Kryptos, a sculpture at the CIA created by Jim Sanborn. On it there are four ciphers, three of which have been cracked. As of the writing of this post, the fourth has yet to be cracked. But just a few weeks ago (Nov 20), “Berlin” was revealed by Sanborn as a clue to the last unsolved section of the cipher. This information was released by the New York Times, but here’s the wired.com article where I first read about it. The clue decrypts 6 ciphertext letters of the last section. This is what cryptanalysts call a ‘crib.’ And most classic ciphers like substitution, shift, and the hill cipher easily succumb to a known-plaintext attack: If you give me some plaintext and the corresponding ciphertext, I can recover the key. It doesn’t sound like this last section is quite as easy as the classic ciphers, though.

One of the other project presentations in our cryptography class was on Kryptos. I also found a presentation on the recently cracked chaocipher very engaging.