BTW the Carmichael function and Carmichael numbers have little in common aside from their author and the fact they concern whether x^b = 1 mod N for x relatively prime to N.

https://www.coursera.org/learn/crypto

Although there are continuums of teaching delivery from muddled to clear explanations of concepts, there are no student shortcuts to escape the irreducible mental exertion to acquire familiarity towards mastery. Uncurious people shouldn't be in the field (no pun intended).

I also added plenty of inline python code blocks students can change and run on the fly.

The reason i wrote this is the hand waving around group theory i saw in other explanations. Namely you shouldn't just say x^y always = x mod m for certain values of y (eg. x^13=x mod 35, even for factors of 35). You should give a detailed, intuitive understanding of why this occurs.

It's an ugly naive implementation, but it's much simpler and more accessible than any real one I've ever seen, and depends on nothing but libc.

RSA is math so it seems like you're trying to shove a square peg into a round hole here.

I don't know how it's taught elsewhere but I feel like I both have "a sufficient grasp of the number theory to really understand what is going on" but also I "should not be implementing RSA for a system that needs actual security" !

Start and end with a reminder to use padding.

Actually if you want to make it not-so-mathy, talking about about how to be compatible with other programs could be nice. How do you import/export public key in pem or der? How do you (de)serialize ciphertext?

disappears into the back room for fifteen minutes

"Yes, it's trivial."