A Look Back on the History of Cryptography

In May, I taught a class on the History of Cryptography at Portland Underground Grad School. I’m extremely grateful to PUGS for asking me to teach, because I’d never done it before. It was a great experience. My students were intelligent and the discussion was good. I learned quite a few things in the process.

Teaching Isn’t the Same as Lecturing

I have a lot of experience with public speaking. I spent time in Toastmasters International and have given many lectures. In fact, here’s a video of me giving a lecture on the art of memory back in 2013.1

I knew that teaching would be different, but I didn’t know what to expect. Luckily, Douglas Tsoi, the mastermind behind PUGS, helped me design my four-week curriculum and gave me a lot of advice. The two main differences that I noticed are that, first, teaching is a lot more like a conversation, and second, you continue following up week after week. Conversation and continuity!

Douglas’s help was invaluable. He’s the reason that PUGS is able to bring in experts without teaching experience while providing a rich educational environment.

It’s Hard to Boil Down Experience

“There is so much to learn! I enjoyed being able to ask questions at will and go deeper into the subject with a knowledgeable instructor.” — An anonymous student

A PUGS class lasts four weeks, and there’s only one class per week. That’s not a lot of time to cover a complicated subject. Going into the class, I just didn’t realize how difficult it is to cram decades of experience into just a few weeks. In our third class, while discussing Phil Zimmerman and the creation of PGP, I realized that I’d been learning about cryptography for over 20 years.

The learning curve in cryptography is staggering. I didn’t realize that going into it, but it’s really difficult to introduce things like the Diffie-Hellman key exchange protocol to people who had just learned to do an alphabetic substitution cipher for the first time. All of my students were very intelligent people, but none of them were computer scientists or mathematicians. My curriculum is going to take some adjustment.

Teaching is Fun

Through this class I met many interesting people. While preparing for the class, I had to brush up on a lot of dusty knowledge. In the process I learned a lot. The entire thing was mentally engaging, socially stimulating, and a blast. I hope that PUGS will have me again, because this class is only going to get better.

If you enjoy learning, you owe it to yourself to take a class at the Portland Underground Grad School. Go check them out!


  1. I embedded this video just to exploit a neat WordPress feature.  

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