The Joy of Cryptography, by Mike Rosulek, is an undergraduate-level textbook introducing students to the fundamentals of provable security, published by MIT Press, and available online as a free, open-access educational resource.
You can file a bug report or make a feature request (for the print or online edition) by starting an issue.
If you are a teacher or student who would like to typeset cryptography in LaTeX using the formatting conventions of The Joy of Cryptography, you can find some resources here.