CS*55 series
The first course happens regularly, while "part 2" has been "2 months away" for at least a year now.
But it's 400 pages and part II and III are not present :|
Also I find the structure kind of odd. I is symmetric, II asymmetric and III protocols. Where do you put lattices, ZKP, lattices, FHE...
Another thing that bugged me: in the Integrity chapter they talk about MAC. Whereas they should talk about hashes, MAC provide integrity + authentication.
This is a common misconception that integrity is enough to protect against a MITM, whereas no you also need authentication. I'm sure this could lead to people just using a hash to secure their data in transit.
The current draft only contains part I. Parts II and III are forthcoming.
The immediate answer to your question is that I only just now tried pdf2htmlEX (https://coolwanglu.github.io/pdf2htmlEX/) and was stunned how good it was. If you are on OSX, one can "brew install pdf2htmlex" your way to happiness. Don't get me wrong: exporting to HTML is a long way from "ebook-friendly" but I feel it is close to the spirit of your question.
Please report back if they authors do agree, as I'm sure you're not the only one interested.