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I asked people if they understood and/or enjoyed the talk Reeds gave. Students seemed to like the talk, and said they wanted more.

I then asked a student to present her solution to the Cubing problem. We discussed Cubing and Cube Inquiry. This was a homework problem. I had gotten a great deal of e-mail about it. Many students didn't find the level of abstraction needed to do the problem approachable. They did the problem by analyzing examples rather than with algebraic reasoning. The problem needs to be rewritten and perhaps more work done in class.

I tried to discuss P vs. NP -- and learned that I hadn't even made
clear what the abbreviations were for. I tried to emphasize that there
seemed to be problems which were intrinsically difficult, that had no
"fast" ways of doing them. I handed out notes on this material **[PDF|PS|TeX]** and emphasized that such
considerations were at the foundation of many modern crypto
protocols. I don't think this material, which seems to be subtle, was
presented as well as it could be.

I then briefly discussed the history of public key cryptography, with
emphasis on the discovery inside the British security apparatus which
predated the public discoveries (as discussed in Singh's *The
Codebook*). I said that in the next two weeks we would meet the
principal ideas of public key cryptography, including Diffie-Hellman
and RSA.

Then I passed out the experimentation homework and strongly urged
people to do it before Wednesday **[PDF|PS|TeX]**. I commented that what I
had discussed was theory, but a sure way of really believed what we
were about to learn was to have some real examples, and we could use
Maple to do what might be tedious arithmetic. Also, I wrote that
"... giving such an assignment would have been nearly impossible 5 to
10 years ago." Students could not have possessed the computing
capacity, and having it so accessible is just wonderful.

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